Author's Note: So I've been HEAVY into the anime Kokoro Connect recently. It's so good and so underrated. I highly suggest checking it out! So I wanted to make an Eremika with Armin and Rubi version. Think of Mikasa as Himeko, Rubi as Yui, Eren as Tachi, and Armin as Aoki. ALSO, this fic will have narration from Eren like in Disappearance of Mikasa.

It was a beautiful late summer morning. Sakura petals fell from the trees, cars drove down the road, and priests swept the stairs of their shrines.

A town bus went by, while an elder lady walked her little Corgi. Standing under a Sakura tree was a 16 year old boy. He had brown hair, green eyes, and was on his phone, wearing his school uniform.

"They're late..", he muttered to himself, as he scrolled through random texts on his phone.

Eren Jaeger waited for his three closest friends, it was almost 7:20 in the morning. Usually he was the late one.

"Eren!", yelled a voice then. Eren glanced up, seeing two figures running towards him. "Oi! You're late!", he waved, grinning.

The girls ran up, stopping. "Who are you to scold? You're always late!", Mikasa pointed out, she blushed a bit around him.

She had jet black hair, shoulder length, and deep bluish black eyes. She also wore a red scarf around her neck, despite it being summer.

"Bloody hell, Eren, you're never early!", Rubi said, surprised. Rubi was Mikasa's age, 16, born until a few months after.

She had long red hair in a ponytail, brown eyes and a large chest. She was not Japanese like the rest, she was Britsh and Scottish, having moved to Japan several years ago with her parents.

Mikasa Ackerman was actually Rubi Zacri's adoptive sister, since they were 9 years old.

"I didn't sleep at all", Eren admitted, shrugging. "Seriously?", asked Mikasa, blinking. "I got a new video game, and was on all night!", Eren explained.

Rubi rolled her eyes. "Eren, you'll be too tired to focus in class", Mikasa pointed out, crossing her arms.

"I'll be fine", Eren assured her. "Honestly I don't know what my little sister sees in you", Rubi pointed out.

Mikasa and Eren both blushed then. "Rubi, what are you talking about?", Mikasa demanded, glaring, but blushing furiously.

"Oh come on, Miki!", Rubi giggled, as she suddenly wrapped her arm around Mikasa's shoulder, pulling her close. 'Miki' was a nickname she gave Mikasa.

"Seriously, when are you going to just tell him?", she whispered then.

"T-There's nothing to tell!", Mikasa yelled, glaring, but still blushing.

"I'm standing right here, ya know", Eren commented. "Listen here, buster! You better treat my little sister like a fucking Queen!", Rubi snapped, protective, as she pulled Mikasa's closer in a protective embrace.

"Sis...can't breathe...your breasts...!", Mikasa stammered, pulling away. "Oh...right, sorry", Rubi looked embarrassed then.

These two are Mikasa and Rubi. They've been adoptive sisters since we were all 9 years old. One could say they were a little strange since they were so close, but after Mikasa's parents died, she latched onto Rubi.

So in the end, their closeness is just natural.

Mikasa is a quiet, intense girl. But she works as the leader of our group, always making sure there's no hurt feelings between us. She's also...beautiful.

I've always loved her, but never knew how to tell her. It was obvious she felt the same, but we both...just were too shy to say anything.

Then there's Rubi...she's certainly something. She's insanely protective of Mikasa, and has the mouth of a truck driver. Which sounds really weird coming from her English accent.

I try to keep peace between us.

"So, where's Armin?", asked Mikasa, noticing his absence. "Late it seems", Eren replied, checking the time on his phone.

They then saw a figure running towards them. "WAIT! Don't leave without me!", Armin cried, running up to them.

"Finally", Eren said, while Rubi instantly blushed.

"You're slow as always, Armin", Mikasa commented. "Sorry! I slept in", Armin apologized, catching his breath.

"Let's hurry, we're already gonna be late", Mikasa said. "Race you all!", Rubi challenged then, running ahead.

"Oi!", Eren yelled, running after her. "Sis, wait!", Mikasa followed.

"Not more running...", Armin whined, but followed.

The four ran to school, and just as Rubi was about to run through the gate, Mikasa jumped on her back.

"Hey! Miki!", Rubi cried, giggling, struggling to hold her sister's weight.

Mikasa dropped off, as she wrapped her arms around Rubi and Eren, while Rubi wrapped her arm around Armin, all of them laughing.

"You both win", Eren concluded, grinning.

"No way, sis didn't jump until I was on school property!", Rubi argued. "I landed on your back after, but I was in the air before", Mikasa corrected.

"I actually agree with Rubi", Armin admitted. The four friends headed inside, and went to class, the school bell ringing.

"We'll be starting today off with some Math", the teacher said. Several students groaned, including Eren and Rubi.

During the class, Mikasa focused on the math problems, while Rubi and Armin did too. Eren fell asleep, his face resting in his hand, as his elbow kept it up, but he snored nonetheless.

"Eren", Mikasa said, softly, poking his arm with her pencil.

Eren continued to snore. "Eren!", Mikasa said a bit louder. "Huh? What?", Eren stirred awake, looking around.

"You need to stop playing video games all night", Mikasa scolded. "Hey, I learn some helpful, legit survival skills on those games!", Eren argued.

"You're pressing buttons on a controller", Mikasa pointed out.

"But...it still teaches you how to survive during a zombie apocalypse!", Eren said.

"Eren, a zombie apocalypse would never happen", Mikasa said. Eren fell quiet, he then blinked, worried.

"Mikasa, it's still too hot out for you to be wearing that scarf...", he said, concerned. "Eren, summer's over. It's fine", Mikasa assured him.

"Almost over, it's still September. Summer break is over, sure, but its still hot out", Eren said, worriedly.

"Eren, I'm fine. You know I don't like taking it off...", Mikasa said, stubbornly.

Ever since I gave her that scarf when we were kids, she rarely takes it off. Even when its hot out. It drives both me and Rubi crazy.

But it does make sense...I gave it to her not long after her parents died.

Rubi focused on the math problems, while Armin appeared to be struggling.

"I don't get it!", Armin sighed, struggling. Rubi glanced at his paper. "Here, look...", Rubi quick helped him while the teacher's back was turned.

"Thanks Rubi...", Armin smiled, relieved. Rubi blushed a bit.

"No problem, Armin", she said. Eventually, it was P.E. Eren was in the gym, practicing basketball with other students like Jean, Connie, Ymir and Reiner.

Mikasa was running track with Rubi, Sasha, Krista, Marco, Bertolt and other students while Armin sat out P.E.

"As usual, Mikasa's the fastest", Armin noticed, walking from the bleachers.

Mikasa ran faster than the others, extremely skilled in P.E. She was way ahead of the rest, her hair flowing through the wind.

"How does she do it?!", Rubi panted, as she struggled to keep up.

After another lap, all the students stopped, while Mikasa continued. "She's something", Armin admitted, watching, as he gave Rubi a cold water bottle.

"Yeah, but she works herself too hard...", Rubi said, breathlessly, as she drank some, and got herself wet with it, extremely hot and tired.

"She still...?", asked Armin, worried. "Yeah...she always overworks herself in P.E. Ever since her parents died...", Rubi replied, worriedly, as she dried her face with a towel.

Mikasa ran another lap, her red scarf was off, and folded on the bleachers by Rubi and Armin. She only took it off during P.E.

"I don't know how she can...", admitted Rubi, her back hurting. Armin looked at her worried. "You okay?", he asked.

"Yeah, might have pulled a muscle again, these don't help...", Rubi admitted, glancing at her double D cup breasts. Armin turned red, trying hard not to stare.

Mikasa ran four more laps, Rubi and Armin watching. "Bloody hell sis, stop...", Rubi said, worriedly, watching her.

Finally, after one more lap, Mikasa stopped, she skidded a beat, but had great balance and grip. She panted, out of breath.

"Sis, here", Rubi quickly handed her a cold bottle of water. Mikasa drank the entire bottle, and gasped for air after she finished, sitting down.

"Were four extra laps really needed?", Rubi asked, worriedly, as she handed her sister another bottle. "I'm fine, sis, really...I needed to run today", Mikasa assured, as she poured the cold water over her, getting her hair and face wet.

"Sis, are you sure?", asked Rubi, worried, handing her a towel.

"I'm really okay, Rubi. Don't worry", Mikasa reassured her, giving an exhausted smile. She dried her face, getting her scarf.

Rubi looked worried still, not saying anything. "I'm really okay, sis. Come on, lunch is in a few minutes", Mikasa said, as she went ahead.

Rubi and Armin followed. "She works out extra hard after nightmares...", Rubi said then. "What?", Armin listened.

"When Miki has nights full of nightmares...well, more like memories of her parents, she works extra hard in track the next day, to distract her mind. As long as she's moving, she can't think about it", Rubi explained, worriedly.

"Oh...", Armin said, worriedly.

After showers, the three soon met up with Eren in their special clubroom to eat lunch. "Finally, I'm starving!", Eren said, getting his lunch out.

"We got a free period after this, so we can chill here", Rubi said, as she and Mikasa opened their matching lunches.

Armin opened his. "I actually have to finish an essay, after lunch I want to get it done on my laptop", Mikasa said, as she ate.

"Which one?", asked Eren, eating like crazy. "Our History one, on World war 2...", Mikasa replied, eying Eren. She knew he didn't even start his.

"Oh..but isn't that not due for two more weeks?", Eren asked, nervously. "Two days", Rubi corrected him, as she ate.

Eren sweat dropped, looking panicked. "Oh well, I'll just write something quick up", he shrugged then, kicking back.

"No wonder you get Fs", Armin said.

"Oh, I brought our drinks!", said Armin, as he set four cans on the table, from the vending machine. "I'll take the Coke!", Eren grinned, snatching it.

"I'll just have the Iced tea", said Mikasa. "Then I'll take the Pepsi", said Rubi. "That leaves me with the juice", Armin said, opening it.

Mikasa then opened her laptop. "Mikasa, you're not even done eating yet", Eren said, surprised. "I'll have to eat while I work, I want this finished today", replied Mikasa, as she opened her iced tea.

"Miki's essay is so long, its like 30 pages", Rubi said, smiling. "Its a big topic", Mikasa said. "Have you finished yours Rubi?", asked Armin.

"Almost, mine isn't as long though", admitted Rubi, sheepishly. "It's well written though, sis", Mikasa pointed out.

She then blinked. "Damn it, I forgot my discs", she said. She always kept her work and files on discs, in case something happened to her laptop.

"I'll go get them, Miki. In your desk, right?", asked Rubi, getting up. "Yeah, thanks sis", Mikasa said, as she finished her lunch.

Rubi hurried out. She entered home room, and went over to Mikasa's desk. She opened it, and find the discs.

She picked them up.

"Hey Armin, are you gonna finish that fried shrimp?", asked Eren. "No, you can have it...", Armin started to say, when suddenly, he was no longer in the clubroom looking at Eren.

He was...in home room. Holding computer discs. Armin froze, at first confused. "What...", he then jumped, covering his mouth.

He had a girl voice...but it was...a strong British accent. He then looked down, and his heart dropped. He...was wearing a girl's uniform, and had...boobs.

"What is...happening?!", he stammered, in Rubi's voice, he then grabbed the mirror that was in Mikasa's desk, and looked.

In the mirror, Rubi's face starred back at him. He let out a panicked yell, and only freaked out more, sounding like Rubi.

In the clubroom, Rubi was suddenly starring at Eren, and sitting next to him, across from Mikasa. "Wait...how...", she began to ask, but then squeaked, hearing Armin's voice come out of her.

"Armin, you okay?", Mikasa asked, as Eren ate the last fried shrimp, not noticing at first.

Rubi looked around for a mirror, she then ran over to the window, and saw her reflection...Armin's face was starring back at her.

"Armin?", Mikasa repeated, looking over.

"Uh...I'm not Armin, sis...", Rubi started, still freaked out from the voice. Mikasa starred blankly at Armin.

"Very funny", she said, not amused as she looked back at her laptop screen.

"N-No...sis, really! I'm...what's going on?!", Rubi panicked, feeling her body, and short blonde hair.

"Armin, come on, its not April fools or Halloween, its getting old", Mikasa said, unimpressed. "Good one Armin", Eren chuckled.

"I'm not joking...!", Rubi cried, but her voice still sounded like Armin.

In the classroom, Armin sat there at Mikasa's desk, in complete shock. "How...how am I in Rubi's body...?", he asked, as he pushed the long red ponytail behind him, off his shoulder.

He then turned bright red, looking down. Rubi's breasts looked even bigger from her point of view. Armin blushed more, as he suddenly couldn't control himself, touching Rubi's breasts, with her hands.

"They're so...soft...", he mused, still wincing every time he heard it was Rubi's voice and not his.

Back in the clubroom, Rubi was still freaking out. "Miki, I'm serious! It's really me!", she cried.

"Armin, seriously dude, its getting old now", Eren admitted, while Mikasa chose to ignore it.

"Its not a joke! I'll prove it! Mikasa! You're wearing your black bra and black kitten underwear!", Rubi blurted out then.

Mikasa suddenly froze, her eyes growing wide, while also turning bright red. Eren turned bright red as well, suddenly starring at Mikasa.

Armin wouldn't know that, only Rubi would since the sisters often changed together.

"W-What...?", Mikasa stammered. "See?!", Rubi cried. "Okay...WAIT! What age did I get my first period?", Mikasa demanded, freaked out.

"12", Rubi replied. Mikasa starred. "One more, to be sure this isn't some joke! Eren, cover your ears!", Mikasa ordered, blushing.

"What...?", Eren blinked. "Cover them!", Mikasa yelled, blushing furiously. She had to ask something only Rubi would know, without a shadow of a doubt, something she would never tell Armin.

"Uh...okay!", Eren did so. Mikasa took a deep breath. "What did you catch me doing a few months ago, that scarred you for life?", she asked then.

"You were masturbating to Eren's photo", Rubi replied.

Mikasa's heart sunk, her head spinning. "Oh my god...", she cried, stepping back. "Can I uncover my ears now?", asked Eren, awkwardly, as he slowly did so.

"I'm telling you...I don't know why, but Armin and I switched bodies...", Rubi said, as she sat down, with her legs crossed, a way Armin would never sit.

"So then...where's Armin...?", Eren started to ask. Rubi suddenly blushed like crazy, while Mikasa glared.

"Shit!", Rubi cried, while Mikasa bolted up.

In the classroom, Armin was still fondling Rubi's breasts, very red.

"How does she...fit them in a bra?", he wondered, when suddenly the door slid open. Armin panicked, jumping, but not removing Rubi's hands from her breasts.

Sasha stepped in, she then blinked. "Rubi?! What are you doing?!", she cried, blushing, and freaked out.

"Uhh...uhh...", Armin started, when suddenly Rubi, Mikasa and Eren ran in. Mikasa grabbed Armin by the shirt collar, glaring dangerously.

"You...are so...DEAD! You little pervert!", Mikasa growled, dangerously. "Sis, that's my shirt you know...", Rubi pointed out, still in Armin's body, blushing furiously.

"I'm sorry Mikasa! I didn't mean anything...!", Armin cried, blushing furiously.

"Get OUT of my sister's body, you hear me?! OUT!", Mikasa yelled, glaring dangerously.

"I don't know how!", Armin cried. Sasha starred at the scene, a look of complete confusion on her face.

"Uhhh...I'm just gonna pretend I didn't see or hear any of this...", she then took off, freaked out.

Mikasa sighed, finally letting go. They returned to the clubroom. "So...how the hell did this happen?", Mikasa asked.

"This is so bizarre..", Eren admitted, seeing Armin sitting like some lady while looking at Rubi, sitting hunched down, blushing and nervous.

"One minute I was talking to you, then I was in the classroom...", Armin said, still struggling with Rubi's long red hair.

"And I was in the classroom, getting Miki's discs, and then...I was back here", Rubi added, as she kept trying to push her ponytail back, but just touching Armin's short blonde hair.

"What the hell is causing this?", Mikasa growled, frustrated.

"That...would be me...", a dark, emotionless voice said then. The group all looked towards the door, seeing a man standing there.

His eyes were empty, his face blank.