Riku's POV (Third Person)

Riku watched as his partner took off with the red-clad hero, a confused look on his face. He would have stood there and pondered more, if it weren't for the beeping sound coming from Chat Noir, and the encroaching Unversed.

"I'm just gonna have to trust her," he said to himself, sighing. Kneeling, he picked up the black-clad hero and draped him over his left shoulder, before standing up straight once more and raising his Keyblade. He cast a powerful Thundaga spell, unleashing a flurry of lightning strikes that dispelled several enemies.

With an opening created, Riku rushed out of the clearing, keeping a firm hold on the unconscious teenager as he searched for a secluded location. Thankfully, the area was deserted and the silverette quickly found an alleyway between two buildings hidden in the shadows with a convenient bench.

He had just set the boy down on the bench when the beeping reached its climax and stopped, followed by a golden light washing over the blond youth. Riku watched curiously as the hero's suit vanished, replaced by a black t-shirt with five, multi-colored stripes going across the chest, an unbuttoned white shirt with its sleeves rolled up, blue jeans, and orange sneakers.

What Riku hadn't expected, however, was a small, cat-like creature to materialize above the hero when the costume vanished. It let out an exhausted breath and began to flutter to the ground, where it would have surely crashed if the silverette had not reached out and caught it.

"Man, anyone get the number off that truck that hit us?" The strange creature muttered with a male voice, rubbing his head.

"You okay?" Riku asked.

"Yeah, just exhausted is all. Some camembert and I should-" He stopped mid-sentence and looked up at Riku with large green eyes. "Who're you?!"

"I'm Riku. Are you Chat Noir's kwami?"

"Like I would tell you," the cat said with a huff, crossing his arms and looking away.

The silverette sighed. "Look; I don't know exactly what's going on here, but I do know that Chat Noir needs help."

Hearing this, the kwami spun to look at the still-unconscious boy lying still on the bench.

"My partner is looking after Ladybug and took off, so all I can tell you is that we were sent here by a mentor of ours to check on a friend of his by the name of Master Fu," Riku pressed.

The tiny creature looked back at Riku with his eyes narrowed, a serious expression taking hold. "Who's this mentor of yours?"

"His name is Master Yen Sid," the Keyblade Master answered.

This response seemed to take the kwami by surprise, but he didn't voice it and instead glanced back at the blond-haired youth. Eventually, he let out a sigh before stating: "I guess I've got no choice but to trust you. I can guide you to where we can get help, but we'll need to avoid being seen. How do you feel about jumping rooftops?"

Hikari's POV

I had just barely made it onto the rooftop of my destination when Ladybug transformed back into her civilian form. I carefully set the teen down in the red-and-white-striped beach chair right before a familiar and exhausted creature materialized. I reached out and caught the kwami before she would have fallen to the ground, already starting a Curaga spell, though I wasn't sure if it would help at all.

I was relieved to see that it had some effect, however, as the kwami groaned and stirred somewhat. "Are you alright?" I calmly asked.

"Ugh, what happened?" Was her reply as she slowly sat up, a hand on the side of her head. When she opened her dark blue eyes, her expression changed to that of nervousness as she quickly questioned: "W-Who are you?"

"Please, don't be afraid," I said, trying to ease the weakened kwami's worries. "I have no intention of hurting you or your Miraculous holder. My partner and I just happened to be sent here to check on the condition of this world and found Ladybug and Chat Noir being outnumbered by the Unversed."

The kwami's eyes widened. "The condition of this world? Does that mean you're a Keyblade Wielder?"

I felt my heart leap, having my thoughts confirmed that she was aware of outside worlds and the Keyblade. I gave a small smile and nodded. "My name's Hikari. My friend and I were asked by a former Keyblade Master to see if this world was being targeted by the Darkness." My smile vanished as I looked at the unconscious girl, before adding more solemnly: "I only wish we could have arrived sooner and perhaps prevented those two from getting hurt."

"My name's Tikki. Please don't feel bad, Hikari; you probably did the best you could under the circumstances." She paused, seeming to realize something, before tilting her head curiously. "How did you know to bring Ladybug here?"

I sighed. "It's a little complicated. I can explain more at another time, preferably with Master Fu present, to avoid any unnecessary details of other worlds being exposed. For now, I'll heal Marinette's injuries and regroup with my partner; although..." My sentence drifted off as I looked at the bracelet on my left wrist. "It may make things easier if she thinks I'm another hero like herself."

"That might be a good idea," Tikki chimed. "If the issues you came to address can't be resolved quickly, having a secret identity may allow you to keep a closer eye on the world. Plus, it will keep Ladybug and Chat Noir out of the loop until everything can be properly explained by Master Fu."

"Then it's decided." Just like back in Atlantica, I focused on the power within my bracelet, picturing some changes to my current appearance. After I felt the transformation finish, I reached out my right hand and started another Curaga spell, the beautiful green light washing over the dark-haired girl.

After a few moments, the teen let out a relaxed breath and her eyelids slowly began to flutter open.

Marinette's POV (Third Person)

The first thing Marinette realized upon coming to was the calming sensation that flowed throughout her entire body. It felt as though she were being wrapped in a cocoon of blankets, warm and inviting. The pain from her fight was quickly becoming nothing more than a faded memory, the aches in her joints, and the throbbing muscles vanishing.

When she tried to open her eyes, she struggled with the weight that seemed to hold her lids closed. Eventually, she managed to push through, revealing her bluebell-colored eyes, but at first, all she could see were faded shapes and colors.

After blinking a few times and allowing her sight to realign, she realized that she was lounging in the chair on the roof of her home; and that she wasn't alone.

Standing at her side and leaning over slightly, a teenage girl was holding out a hand, which was emanating a green aura that was the warm power Marinette has sensed.

Seeming to notice that her patient was awake, the stranger gave a gentle smile as she pulled her hand away and stepped back, allowing Marinette to take in more details of their appearance.

She looked to be only a few years older than herself, perhaps no more than eighteen or so. She was also half a head taller and had an athletic build. Dark-brown hair was brushed to the left side of her face and loosely braided with dark-blue ribbons woven in, draping over her shoulder and ending just past her chest. She wore a form-fitting t-shirt in a sky-blue shade -with her right sleeve black and her left sleeve white- and a darker blue hood pulled back. Her pants were a grayish blue in a style similar to cargo pants, held up by a black sash that blew slightly in the breeze, the legs tucked into knee-high boots that mirrored the shirt sleeves in color.

What really caught Marinette's attention, however, were the stranger's icy-blue eyes -which seemed to give her a sad yet warm persona- that were tucked behind a simple domino mask the same color as the ribbons in her hair.

"Oh thank goodness. You're finally awake!"

The younger teen turned to see her kwami zoom up to her and hug her cheek. "T-Tikki!?" The girl's eyes darted back and forth between her partner and the masked individual, her eyes growing wider by the second and she tried to speak, but was only able to stammer a few syllables.

"It's okay," Tikki reassured. "She's the one that saved you from those monsters and healed your injuries. We can trust her."

Marinette rose to her feet and placed her full attention on her supposed savior. "Who are you? A Miraculous holder?"

The older girl shook her head. "I do not possess a Miraculous such as yourself, but I do have powers, not unlike said magic treasures. As for my name, you can call me Tsubasa."

"Tsubasa?" Marinette repeated, the name sounding extremely foreign as it rolled off her tongue.

Tsubasa nodded. "My partner and I came here at the request of our mentor, and just happened to find you and Chat Noir taking quite the beating from the Unversed. I brought you here upon your kwami's instruction, and my friend no doubt did the same with Chat Noir."

Marinette tilted her head. "Unversed? What are-"

The teen's sentence was cut off when the voice of her mom could be heard coming from the open roof hatch.

"Marinette? Are you up there?"

"Y-Yeah, Mom," said girl replied nervously, turning to the hatch and ensuring her mother wasn't peeking out. "I'll be down in a bit." When she looked back to continue her previous conversation, however, Tsubasa had her back to the youth and was perched on the rails lining the roof.

"There will be a time and place to explain everything. For now, though, allow yourself and your kwami some rest." The stranger looked over her shoulder and, with another smile on her face, added: "We will see each other again soon, Ladybug." With that being said, she jumped off the railing.

Horrified, Marinette rushed to the edge, only to look down and see large wings appear on Tsubasa's back in a flash of light, lifting the teen into the air and quickly disappearing from sight.

"What on earth did I just see?"

Adrien's POV (Third Person)

"Come on, dude. Wake up."

The blond teen groaned, the familiar, annoying voice of his kwami breaking through the haze of unconsciousness and rousing him. When his emerald-green eyes opened, the first thing he noticed was the cream-colored ceiling with brown-boarded accents. He turned his gaze slightly and saw familiar Chinese-style decorations, including a screen divider and bamboo furniture.

"Welcome back," Plagg chimed, hovering over Adrien. "You had us worried there."

"Plagg?" Adrien sat up slowly, a hand to his head. He turned to his left, immediately finding the Guardian of the Miracle Box sitting cross-legged on a wooden stool, sipping from a cup. "Master Fu? What happened? How did I get here?"

Said man lowered his cup and sighed. "You and Ladybug were ambushed by a dark force I had hoped you would never have to encounter," he explained.

The teen looked down, trying to recount the events following to him passing out. "I remember we had just finished defeating an akuma when these strange monsters came out of nowhere." His eyes widened, suddenly realizing that his precious Bugaboo was not with him. "What happened to Ladybug!? Is she alright! Where is she!?"

"Woah, dude, calm down," Plagg said, trying to ease his owner.

"There is no need to be concerned," Master Fu added, regaining the young hero's attention. "Thankfully, some new allies were able to subdue the threat before any real damage could be done and managed to get you and Ladybug out of harm's way before you both transformed back."

"New allies?" Adrien repeated.

The guardian nodded before his eyes drifted over to the lone window.

The blond followed his line of sight and was surprised when he noticed that they were not alone.

Perched in the open window with his back leaning against the side frame was a silver-haired male, perhaps being only a few years older than Adrien, with his eyes gazing at the city outside. He had a strong physique, with a lean but well-toned torso and slightly muscled arms, his fingers appearing slightly calloused, perhaps from wielding some kind of weapon. His outfit consisted of an opened white vest with yellow and blue trimming on the bottom and collar, a black zippered top underneath that was slightly undone on the bottom, exposing a bit of his navel, violet-blue cargo pants, gray and white sneakers, and a white arm warmer on his left forearm.

When the stranger turned back to those inside, Adrien was even more shocked by the stunning turquoise eyes he possessed, an icy fire seeming to burn inside the orbs.

"This young man and his partner had just arrived in the city when they came upon you and Ladybug," Master Fu elaborated.

"It's good to see you weren't too badly hurt, given how hard that Unversed slammed into you," the silver-haired teen stated, his focus on the younger hero. "I just received word that Ladybug is safe as well. She was a little bit more banged up, but my partner was able to heal her completely."

Adrien didn't immediately respond, instead turning back to the older male with a questioning look.

Master Fu smiled. "They can be trusted, Chat Noir. They were sent here by their mentor- who happens to be an old acquaintance of mine- to help with this new threat."

The teen nodded, not completely satisfied with the clearly vague response, but decided to let things be for the moment. He got to his feet and approached the window, offering his hand to the newcomer. "Thanks for saving us. Got a name I should call you by?"

The silverette gave a small smile and turned his body inside before stepping down from the sill, revealing that he was an entire head taller than Adrien. "It's Riku," he replied, accepting the younger boy's hand and shaking it.

"We will discuss our current situation in the near future," Master Fu offered, catching the two heroes' attention. "For now, Chat Noir, I suggest you and Plagg return home. You both need the rest. I will call for you and Ladybug soon."

Adrien nodded. "Thank you, Master. Come on, Plagg." He gave a final farewell to Riku before heading out the door.

Riku's POV (Third Person)

A few minutes earlier...

Riku gazed out at the beautiful city now known to him as Paris. He had traveled to a world in the Dream Realm that had a city of the same name, but that world and this one were clearly different. For one thing, the Dream world was clearly set in the past, while the one he was watching now was more modern, somewhat like a mix of Traverse and Twilight Town, only bigger and with far more people.

"Riku."

Said silverette's attention was pulled from the view and to the familiar voice echoing through his head. "Ayame? Is everything alright?"

"Everything's fine," the spirit replied. "Hikari was able to get Ladybug home safely and heal her injuries. Where are you?"

"Master Fu's apartment. That kwami thing Hikari spoke of led me here to get Chat Noir patched up." He turned to look at the room and saw said hero coming to. "Looks like he just woke up."

"That's good to hear. Hikari's heading your way now. She'll be there soon."

"Alright; I'll let Master Fu know."

Shortly after Chat Noir and Plagg leave...

There was a knock on the door to the apartment, followed by a familiar voice.

"Riku? Master Fu?"

"Come in, child," said elder replied.

The handle turned and Hikari stepped inside, quickly closing the door behind her. She approached the mat Riku was kneeling and got to her knees as well, bowing respectfully. "It's an honor to meet you, Master."

"I could say the same," the guardian replied. "From what Riku has told me, your quick thinking not only saved Ladybug and Chat Noir but also kept their identities from being revealed. Tell me though; how is it you knew what to do?"

Hikari looked to Riku, who nodded his head in approval. Master Fu knew of outside worlds long before their arrival, so telling him about Hikari's world most likely wouldn't have any negative effect on the world order. With Riku's support, she explained to the guardian the gift her world possessed and how she knew of this world through a television show.

The elder hummed in though once Hikari had finished, his eyes closed and arms crossed as he seemed to go over this new information. Perhaps a solid minute had passed before Master Fu reopened his eyes and smiled. "We are indeed lucky to have you here, young Hikari. It certainly makes things easier to explain."

Said Keyblader chuckled and nodded in agreement.

"Shall we begin then?"

Both teens nodded and Hikari was the first to speak.

"A group known as Organization XIII is currently going from world to world, spreading Darkness through the use of Heartless. However, one member has taken control of my brother's heart, using him as a vessel to control creatures known as the Unversed, which were what attacked Ladybug and Chat Noir. These monsters are very different from the Heartless, as they spawn from and feed off of negative emotions.

I'm almost certain now that the one controlling my brother is using the knowledge we possess of other worlds to coordinate attacks on places that would usually either be inaccessible by normal means or hidden from those that weren't previously aware of said world."

"I see," Master Fu voiced.

"My concern is that the Organization may attempt -if they haven't already- join forces with

Hawk Moth," Hikari continued. "With his power over the Akuma to pray on the negativity in people, the ensuing chaos if someone is Akumatized could create extremely dangerous Unversed."

"I agree. Ladybug and Chat Noir have never faced foes like the Heartless and

Unversed," the elder stated in concern. "I also fear what your brother's captor will do with the information he has of our world. Marinette and Adrien's secret could very well already be compromised."

"I'm not so sure that's the case," Riku said, finally entering the conversation.

The other two turned to him with surprised expressions.

"What do you mean, Riku?" Hikari inquired.

The silver-haired teen crossed his arms over his chest. "It's been weighing on my mind since we left Mew's world. When we went to that village, we learned that Genji was the one controlling the Unversed. However, not once did the Unversed go after the villagers violently; just kept them confined to their homes. We also confirmed he had taken the village hostage only in hopes of drawing you out. To be honest, if any other Organization member had been there calling the shots, I don't believe anyone in that village would have still had their hearts by the time we arrived. Do you see where I'm going with this?"

Hikari seemed to ponder over this information before her eyes grew wide and brightened upon the realization. "Genji had no intention of hurting anyone not directly involved with me. He made sure that the Unversed left everyone else alone, which means..."

Riku nodded. "Vanitas may not have as much control over Genji as we thought, he finished. "We may yet be able to get your brother out of the Organization's grasp, but for now, we need to focus on the safety of Paris."

"Right." It appeared as if the heavy clouds that had been hovering over Hikari had somewhat vanished, the thought of rescuing her brother no doubt encouraging her on. She turned back to Master Fu and continued- "I'm sorry I dragged my personal issues into this."

"Do not apologize," the guardian replied, smiling warmly. "Family is very important; make sure to hold on to them."

"Thank you, Master." Hikari gave a smile of her own. "As for the safety of Ladybug and Chat Noir, it had crossed my mind also in regards to their civilian identities being revealed. We can't place our faith in the hopes of Genji not telling anyone, which is why I had disguised myself in front of Ladybug so that if I had to keep a closer eye on her or Chat Noir, they would be none the wiser as to who I am."

Riku smirked. "Let me guess: you've already thought this through and have a plan."

The dark-haired teen turned to him and gave a mischievous smirk of her own.

General POV

Marinette wiped the drowsiness from her eyes as she stepped into the doors of Collège Françoise Dupont. She had struggled to get any rest the previous night after the incident with those strange creatures and the mysterious "Tsubasa". While the winged hero had indeed saved her and Tikki ensured she could be trusted, knowing someone knew her secret identity was somewhat unnerving.

When she reached the second floor and opened the door to her homeroom, Marinette was greeted by an unusually chatty classroom. Her classmates were talking amongst one another with energetic voices, a few seeming particularly hyped for some reason.

"There you are, girl," Marinette's best friends, Alya, chirped as she approached the confused teen. "We just got the coolest news."

"What is it?" The blue-eyed girl asked.

"We're getting a student teacher in our class," Alya explained. "Apparently they're part of some international program that allows those interested to see what it's like to teach in different countries and our school is participating in it."

"Miss Bustier told us the student isn't that much older than us and they're from Japan," Nino pipped in from his desk just a few feet away.

Marinette tilted her head, still seeming confused. "How come we're only just now hearing about this?"

"Apparently the student had applied for the program and just so happened to be visiting Paris when they were approved," Adrien answered, joining the conversation. "Guess they got lucky being assigned to a school so close."

"I don't see why everyone's so excited," a snarky remark sounded, causing the four to turn and see Chloe sitting on her desk, inspecting her nails. "I mean, it's not as though whoever it is is a celebrity or something. Plus, who's to say they're even capable of running a class, much less one from a different country than their own?"

"Which is exactly why this program was created."

Everyone grew quiet as Miss Bustier entered the classroom. The clusters separated as they took their respective seats, still anxious to hear more about their class's future guest.

Once her students had settled, Miss Bustier continued. "The Wayfinder Program was started in the hopes of bringing together different teaching methods from all over the world while also showing newly graduated students what working as an educator can offer them. Our school is one of the first to accept a student from this program, so let us lead as an example of how this program can be beneficial to the participant, the school, and education as a whole." She looked to the door before calling out: "You can come in now."

The air stilled, all eyes falling to the door as the handle turned and opened. Was the student-teacher a male or female? Were they handsome/beautiful? Did they have an accent? All these questions raced through the students' thoughts in anticipation.

The guest stepped into the room and was what no one had anticipated. They had been told the student-teacher was not much older than themselves, but they didn't believe they would be that close. Rich, dark-brown hair cascading down their back fluttered slightly as they approached the front of the class. When she turned to face the students, a warm smile and stunning turquoise eyes greeted them. She wore a navy-blue blouse with black slacks, black flats, and a unique necklace of two angel wings in the shape of a heart resting just below her collarbone.

(A/N: For the sake of simplicity, the main language spoken will be implied English. Apologies to any French-readers.)

"Hello everyone," she greeted with a strangely American-sounding accent. "My name is Hikari Kurai and I will be with your class for the next week. I hope we can all get along."

Hikari's POV

It certainly had been a gamble to get this far. Part of my plan had heavily relied on the school's principal not digging too much into the "program", which was just a little thing I had Cid put together, then me sneaking into the school and downloading it onto the principal's computer. It would show up as an email with a "link" to the "program's website", but I had to really cross my fingers and hope he would accept the request to "send a student."

I had at first felt bad for deceiving the guy, but it was the best way I could think of to keep a watch on Adrien and Marinette, as enrolling in the school so late in the term would raise too many alarms and take too long anyway.

As I heard Miss Bustier write my name on the blackboard behind me, I glanced at each of the students briefly. They all had curious looks on their faces, even Chloe, probably curious as to who exactly I was, but waiting patiently. Marinette and Adrien looked to be in good health, the previous day's events not seeming to weigh on them too much.

There was a clink as the teacher set down her chalk. "Alright, class. Since it's Hikari's first day, why don't we get more acquainted and make her feel welcome?"

"If it's alright, I had an idea I think everyone would enjoy," I explained. When Miss Bustier nodded, I continued. "It's sort of like a game. We did this on my first day of kindergarten and it helped the students connect with one another, but I'll tweak it slightly since I'm sure you all know one another pretty well already. So how it works is each student introduces themselves, tells the group, or in this case me, something they think I should know about them, then ask me a question."

The class began to chatter once again, seeming to like this plan.

"That sounds wonderful," Miss Bustier chirped. "Why don't we go by roll-call order?"

End Note:

So, the next chapter is going to basically be a big Q&A about Hikari and sharing little pieces of information about some of the Miraculous Ladybug cast. It will be completely optional and won't hold anything significant pertaining to the overall story. However, if you wanna learn a little bit more about Hikari (as well as her siblings) and some fun facts about Miss Bustier's class, please continue on. I will hopefully try to get the next actual chapter up within a few weeks, but I'm currently busy with work and remodeling my home. Maybe I'll have a new Lost Worlds chapter up sooner since those are mostly already rough-drafted. Until then, stay safe and stay healthy.