A/N:

Rosylen: Thank you for your review! I'll think about posting this one on AO3, since my KHRxBNHA is already there. Thank you for the suggestion and reading this far. God Bless you!

Anyway, go on. Mwahaha!

Chapter Twenty-Eight

"Na, Ritsu-chan." He called out to Ritsu who appeared on his phone screen.

"Hi, Tsuna-kun!" The girl greeted cheerfully.

He gave a small smile as a greeting too. "I want to make a deal with you."

The AI's eyes shone with interests. "A deal?"

"Yup." He answered before tapping on his phone and showing her his own goods for exchange. "Will you hear my conditions?"

Ritsu went on sage pose before looking at him. "Okay."

His small smile stretched a little wider.

Tsuna ate the pudding Karma gave him. The redhead raised a brow at him, but he only shrugged. It's not like he can eat things like this everyday. He may be a pastry chef, but he can't eat his own creation if he wants them stay inside his stomach.

"You should've helped her make it." Karma said as they took more spoonful of the sweet.

"She has it already in her hands, so why do some corrections when it's already there? And besides," He leaned back and took another. "I like how she improvised it."

"Should I take that as a high praise from a pastry chef himself?" Karma jabbed with a smile.

Tsuna chuckled openly. "You may. It touched my standards. It did to yours too, right?"

Gold eyes looked down to the cocktail of pudding in his hand. "It did."

He gave a small smile.

Kayano asked their help to make a pudding that will assassinate Koro-sensei as he ate. Although he's against using food as an assassination material, it can't be helped. There are a lot of assassins who uses poison on food, and there's Bianchi in general. Besides, he wanted to see if Kayano got the needed solution for a big pudding to stand alone since she wanted to direct the whole thing herself.

He followed orders and listened to her explanation. Tsuna was really impressed with her use of Agar with the gelatin for the base. It was also the same solution he came up with, other than some other ingredients that he experimented for a pudding to not crush on its own weight. The wafers too that explode different flavors for different parts of the pudding. Even the use of coolant was good. It was pretty innovative that Tsuna nodded at her genius work. He should be laughing at the reason why she moved though. It was for the eggs that should have gone to waste, but the base of pudding was eggs, so it can't be helped.

Either way, Koro-sensei prevented the explosion, again, and served the good ones for them. It's a good treat for a hard work too. So, Tsuna is pretty happy about it.

"Oi Tsuna."

He turned to Terasaka who called him. He didn't see some gold and blue eyes turning a little dark at the casual call of his name. "Yes, Terasaka-san?"

"Where's my pliers? You took it the other day and you haven't given it back." The other demanded, a hand under the glass of pudding.

"You need it already? I was going to keep it for a year." He kidded while rummaging on his bag for the pliers. "Thanks for it, by the way. I finished what I needed to do just this morning because of it."

"What did you need it for anyway?" Terasaka queried as the brunet placed the tool on the table.

"I wanted to dismantle some important things. That's all." He waved off. "So thanks."

"Yeah yeah. And it's Ryouma, idiot."

He stared at the other's retreating back. "Already? I didn't even permit you from calling me 'Tsuna'."

"What? You want to take it away from me?" The noiret playfully threatened from his seat.

"Can I even do that?" He asked with a blink of his eyes. "Besides, it's not like I can ask you not to call me that. You're as hardheaded as a rock."

"Then then, can I call you Tsuna too?!" Yoshida asked from his seat. It took Tsuna by surprise. "Or it could be Yoshi to be different."

"Tsuna is fine." He permitted. "I want to use Yoshi as an alias in the future." He took a spoonful of the pudding and ate. "You can call me 'Tsuna' if you want to. It gives a familiar feeling."

Muramatsu and Yoshida looked at each other with these big grins, before Muramatsu turned to him. "You can call me Takuya or Taku."

"Taisei for me." Yoshida waved.

Tsuna blinked before he gave a small smile. How nostalgic. "Nice to finally make you as my friends, Takuya, Taisei."

The two grinned wider at him.

"Well, what do we have here, Terasaka?" Karma casually called out as he sat on Tsuna's table, ruffling the brunet's hair. The latter didn't mind and ate more of the treat.

Ryouma only scowled and turned away. It made the redhead laugh.

"Karma," The brunet called out, eyeing the other's cup of pudding. "Can I have one last taste on your pudding?"

"Eh? You're done with yours?" Karma asked and placed his on the table. "You're a mess, Tsuna."

"I am?" Tsuna asked and pulled out his hankie. "Where?"

"Here." The two turned to Nagisa who took the cloth and wiped the mess off from Tsuna's mouth. "You're like a child, Tsuna."

Red sprinkled on those pale cheeks. "I didn't know."

"It's fine." Nagisa smiled while folding the cloth.

Tsuna didn't see the competitive stare-off between Karma and Nagisa against Terasaka. The whole class watched them interact and sweat dropped at that. Those who knew Tsuna from the main building only sighed. The brunet will never know. Koro-sensei only 'nyaruhuhu'-ed at the side.

Tsuna went on his usual routine for the day. Although Karma and Nagisa were a little close, he didn't really mind. Koro-sensei was quite interesting that night too. He kept on talking about Terasaka, Nagisa and Karma. He wondered why. The next morning, he wasn't surprised when half of the cameras he dismantled were already stored. He wonders if the disciple will figure out who cut their wires off.

"I wonder what's our next lesson in P.E." Mimura asked aloud while they change for their P.E. uniforms. "We were done with explosives, right?"

"Yeah. I still can't get over the fact that we cut off the sky-blue wire over the red one." Okajima said before turning to them. "Hey, Sawada. Why didn't you participate in the explosive lesson?"

All boys turned to the brunet who was fixing his shirt. "I was okay with watching."

"But it's pretty different from actually doing it." Mimura argued.

Tsuna nodded as he took a rubber bond from his wrist. "Yeah. But I don't like explosives. They give me bad vibes." He gathered the tail end of his hair and tied it. "I could ask you about it whenever I feel curious. I heard you two are pretty good at disabling it as Takebayashi-san is good at assembling it."

The three mentioned names blushed at the praise.

"Let's go, Tsuna." Taisei called out to him, with Ryouma and Takuya beside him. "Seems like Karma is skipping class again."

"I figured." He replied as he walked towards them.

Tsuna followed the three to the field. He listened to their chatters, and chimes in whenever he feels like it. Ever since Ryouma regretfully collaborated with Shiro and Itona, their group went active on the classes. Especially with the assassination attempts and P.E. classes. It was pretty interesting since all of them are good with the practical part of the curriculum.

When they arrived, he was waved offer by Kanzaki. He excused himself from the three and crouched beside the girl. Kanzaki gladly invited him to the arcade that weekend. He mentally checked his schedule and told her that he's only available by one up to three of afternoon. They were able to set their game by then.

He made himself comfortable beside Kanzaki when the others tinkered to their spots, followed by Karasuma-sensei. Nagisa, Kayano and Sugino sat by them too. He eyed Sugino who glanced at them suspiciously. He didn't mind. It was kind of expected for the other to feel like that since he has some feelings for Kanzaki. He wonders if the girl knows though.

"Settle down." Karasuma-sensei said as he stood in front of the class. Everyone went quiet after a second. "For your second semester's practical assassination training," The teacher raised a finger to make a point as black eyes surveyed them. "we will move on from explosives, to your next foundation of free-running."

"Free...?" Nakamura trailed off.

"Running?" Sousuke continued.

Karasuma-sensei nodded. "For example, let's say you were to head for that lone pine tree over there." Then he pointed at the tree he was saying before turning to them. "Mimura-kun, an estimate is fine. How would you do it and how many seconds would it take?"

Tsuna looked over too as the class did with Mimura.

"U-mm..." The teen uttered in contemplation with his eyes surveying the possible route. "First, I'd crawl down this cliff in ten seconds. Jump over that stream at a narrow point, go around the right, where there's no bush, and finally climb over that rock." Mimura sat back and said his estimated time. "I'd say getting there in a minute sound good."

Brown eyes traced the route and kept his face blank. Nah. He can take that by ten or less if he was being chased down by some of his bullies.

"Okay. I'll try going." Karasuma-sensei said and passed a timer to Mimura while pulling off his necktie. "Time."

The class stood up as the teacher stood by the edge of the cliff and facing them.

"This is the application of the athletics and rock climbing from the first semester." Their teacher continued to explain. "What free-running cultivates is the ability to gauge your physical strength. Ukemi technique." Black eyes scanned them again, meeting the brunet's eyes momentarily before moving on. "The ability to measure the distance to and the degree of danger of the footing in front of you. If you can do this," And he tipped back. "any location becomes a field possible for assassination."

Tsuna watched Karasuma-sensei do a free fall and touch the ground with a just a mini-second, before making a flip and jumping on a rock, used it as a leverage to leap for a great distance to near the stream. He did a somersault to cross the running water and landed far from the stream. Perhaps the heel of his foot didn't even touch the ground when he jumped again to reach a tree branch, used that momentum to leap for the lower part of the pine tree's rock then exerted a good force to jump for a high spot on the adjacent rock before grabbing the closest branch of the tree.

Tsuna can't help himself from clapping in amazement. The brunet could've done the same thing, except he'll only use a good momentum to run the walls and reach the tree.

"What's the time?" Karasuma-sensei asked from his dangling position.

"T-Ten seconds." Mimura answered, equally surprised.

"A technique to move down a path that doesn't exist." Karasuma-sensei said while shaking off his left hand. "If you train thoroughly and master this, it would even be possible to travel from building to building by foot."

"W-Wow." His classmates murmured in amazement.

"However, this is the same as the explosives." The teacher warned as he let go and landed safely on the ground. "If you attempt a high-level technique as a beginner, it would lead to your death. The ground on this back mountain is soft and is well-suited for training. Trying this in a dangerous area or outside this back mountain, or using techniques outside of the ones I teach are strictly forbidden. Got it?"

His classmates took at each other before cheering, "Got it!"

The training started when Karasuma-sensei came back with the same time. To say Tsuna was stretched for the first time in the past five months was an understatement of the year. He hasn't done some movements akin to parkour tricks for the past months. Well, except when he ran away from the bullies after getting beaten up, the usual P.E. activities he doesn't skip and the vacation. Anyways, his muscles burned with all the circus tricks they were asked to do multiple times. They were even taught of how to jump on tree, on rocks, do some simple transitions and such.

Good thing he could sneak in and out of the clinic to get some painkillers. He did gain some muscle mass, with Koro-sensei's incredible food guides. But his muscles still burn from the exertion. It was really visible that his Manager Hariko pointed it out. That evening, he eyed Koro-sensei with curiosity when the teacher asked him if he likes free-running activity. He said 'slight' since it induces muscle pain.

Either way, the training continued on for days so their bodies get used to the movements. Everyone seems to get the hang of it. Of course, there are some who excelled in it. The brunet didn't even try. He'll just have to hide and blend with the objects to hide anyway. Koro-sensei keeps on asking him about the activities every free time. He only stopped when Tsuna answered that it became something like a good exercise since he could do amazing flips.

He should've known.

The next morning, he arrived on Koro-sensei arresting him and Karma for coming inside the room together. The two eyed the teacher weirdly and continued to their seats after evading the handcuffs. The others, who came in earlier than them, shrugged when their eyes met. It can't be helped. Koro-sensei must have something in mind that day for them. His intuition didn't alert him of anything too.

Tsuna sighed as he watched Koro-sensei arrests more of his classmates that uses the door to enter the room with all the mundane reasons he could think of. The yellow teacher is cosplaying as an American cop for some effects too, complete with the blue overall uniform, a self-made badge by the right breast, the cap with a small visor, sunglasses and the bubblegum. He looked like one of those fat lazy bummed American cops who likes to make fun of 'shady' teens by abusing their authority.

"-I had to look for it-"

"We're late, aren't we?" Koro-sensei queried cockily to a stunned Fuwa with a blow of his bubblegum and putting the cuffs on her. "You're under arrest." Then there was silence before he started to snicker as he released the girl for her to sit on her spot. Fuwa eyed Koro-sensei in suspicion.

"What are you doing, Koro-sensei?" Kimura asked aloud for all of them. "What's with that dirty cop look so early in the morning?"

The teacher snickered his laugh again. "It seems like you've all been doing some free-running as of late. Since you've gone through all that trouble, would you like to try playing a game which uses that skill?"

"A game?" Ryouma repeated, looking bored with the idea. "It's probably just some lame-"

"It's cops and robbers! A 3D game of tag using the entire back mountain!" Koro-sensei exclaimed enthusiastically after putting a scarf around Ryouma's head, making the teen look like a traditional thief. Tsuna and Karma laughed at their classmates after they looked at each other.

The class murmured.

"I will have you all take the role of the robbers. Using the techniques you've learned, please escape throughout the mountain and hide. The role of the cops on the chase will be-" Koro-sensei pointed a finger on Karasuma-sensei, who went indignant with the idea, and to himself. "Karasuma-sensei and myself. In the instance that we cannot tag everyone within the first hour, I will use Karasuma-sensei's wallet to buy everyone cake."

"Hey!" Karasuma-sensei shouted, but was, again, ignored.

"On the other hand," The teacher raised two of his fingers. "if everyone is caught, your homework will be doubled."

That declaration caused a chaos.

"Hold on a sec!"

"You expect us to run from you for one hour?!"

"No need to worry about that." The teacher placated easily with his arms crossed. "At first, Karasuma-sensei will be the only one on the chase. Sensei will be on standby in the jail space on the schoolyard. I will only move out in the last minute."

A moment of silence.

"Alright, let's give it a go, you guys!" Isogai yelled at them with exuberance.

"Oh!" The class yelled back in reply, equally excited with the thought of cake and no double homework.

Tsuna was pulled by his usual group (well, he didn't really join them during the summer vacation explosion since he didn't want an awkward air with Karma and his tension, but still!) after changing. He was being pulled by Karma and Nagisa as the others chatter around them.

When they were given the 'go' signal to go and run around in the mountain and hide, he was pulled to a direction again.

"Wow!" Nagisa interjected when the brunet reached the top of the rock they were walking by. "You're amazing at this, Tsuna."

"Of course, he is." Karma smiled as he easily leaped from one rock to a tree. "He has been doing that since elementary."

"I wasn't that bad." He defended. His mind made him remember the things he used to do back then.

"What? Really?!" Sugino queried, his expression lit with amazement. "You do, Sawada?"

He scanned the eyes that gazed at him expectantly before looking away. He saw Hara and Ryouma's group from afar. "I do, until I was transferred here and last semester."

"That's so cool." Sugino gushed.

"It's not really advisable to use outside though." He said as he dangled on a tree branch with both hands. "I almost lost some limbs just to evade from hitting people or falling on a building due to a wrong footing or failed estimation of distance." He made a small spin before doing a crouch on the side of the branch and did a frog leap for the next tree.

(Sawada facts no. Thirty-seven: He has been doing free-running since elementary.)

"Na, Sawada-kun," They all turned to Kanzaki who smiled. "you look healthier."

Tsuna patted his cheek with a hand as the six ogled at him to confirm the difference. "Do I? I don't really feel different, except for being well rested in some days even if I have four to five hours of sleep every weekday."

"Your complexion is brighter too, Sawada-kun!" Kayano seconded as they neared. "You don't look sick too. It's like, you've been positive!"

"I-It's true!" Okuda ditto-ed with a nod, still appearing shy with how she grips the hem of her shirt. "A-And you're participating more in class! Sawada-kun became more approachable."

"Oh?" He blinked at that before smiling a little. "Thank you. At least one of my missions is accomplished."

The six felt their hearts thumped at how cute the smile was.

"Anyway, do erase your tracks." The brunet pointed out as he pulled his phone from his pocket and checked on Ritsu. "Karasuma-sensei is a hawk. He will see some evidences that will point at our directions if you become careless."

"E-Eh?!" They exclaimed.

He blinked and looked at them. "You didn't know?"

"Sugaya-kun, out!" Ritsu announced from his phone.

Karma, Nagisa and Kayano looked over to see how many were out.

"Wah?! Ten already?!" Kayano exclaimed in surprise.

Brown eyes looked around. "Let's move away from here. I saw team four moving at our left awhile ago."

"Yeah. Let's go." Nagisa nodded.

They moved a little near the school. The six questioned him for his suggestion. So, he reasoned that sometimes, they need to hide right under the enemy's territory since it is the unlikely last place they'll search at.

"Who got caught?" Karma asked to them.

Kayano immediately took out her phone and checked Ritsu.

"Bitch-sensei, out!" The AI said cheerfully. Well, she is part of the cops and the one to inform Karasuma-sensei who's in and out.

"Oh no." Kayano's face paled with fear as she lamented. "We keep getting done in. It's a back mountain massacre."

"Weren't we just being arrested?" Nagisa pointed out.

"It's the same thing!" The girl argues, making Karma, Kanzaki and Tsuna snicker at her exaggeration.

"Ah!" They all turned to Okuda who uttered that "But this is cops and robbers, right? Then-"

"That's it!" Sugino supported immediately, getting the gist of Okuda's reasoning. "If we tag the robbers in the jail cell, we can release them!" Then he jumped to the nearest rock. "Let's go save them and go back to the beginning!"

"I'll stay here." Tsuna voiced to Karma and Nagisa. "I don't want Karasuma-sensei to suddenly get all of us when he gets a gist that we're going to free everyone. Even if there is Koro-sensei in the jail circle."

"I second." Kanzaki smiled at them. "We can hide until the last minute."

"Okay." Nagisa said as Karma and him glanced at each other. "We'll be back later."

"Good luck with you guys." Kayano cheered for them.

When the three weren't in sights anymore, Tsuna led the girls to a covered area and slumped on a rock there. He checked his phone as the number of captures get high. It can't be helped. Karasuma-sensei is good at this since he's part of the special force.

He looked up when he noticed the girls peering over the open part, just as his intuition poked him in soft warning. The four of them stilled when they heard some rustles and panicked voices approaching before they heard a soft, but strong pat on some parts. Four pair of eyes glanced among them. Okuda slowly put her hands to her face to cover her mouth and nose before closing her eyes. Kanzaki stayed perfectly quiet while Kayano bowed her head, still paling. They all waited in bathed breaths.

It didn't take a minute for Karasuma-sensei to pass by though, not even glancing at their place. When his intuition gave him an 'ok' sign, he gave a huge breath of relief before looking at Ritsu who notified them that all of the old captured 'robbers' escaped. The girls cheered before slumping again when the AI said that Ryouma, Taisei, Takuya and Yada were out.

The whole next thirty minutes became like that. Karasuma-sensei kept on tagging out their classmates— passing by their hiding spots a few times, while the robbers kept on getting out too within a few minutes in jail. According to Okajima, they did some 'shady' things to convince Koro-sensei of letting them go. To say he lived up with his bad cop cosplaying is an understatement.

"We're back!" Sugino called out when the three arrived.

"Here!" Kayano waved them over to their hiding spot.

"Why are you there?" Nagisa queried while inspecting the place.

"It's the best hiding spot." Kayano grinned. "Sawada-kun led us here. Karasuma-sensei passed us a lot of times and he never thought that we're here."

(Sawada facts no. Thirty-eight: He's good with hiding spots.)

"Oh. That's pretty good." Sugino nodded before turning to Tsuna who hid his phone away after checking who got caught again. "Group one wants to team up with you again for a distraction mission."

He slowly blinked in surprise before inclining his head to the side. "Why me?"

"Kimura told them that you're good at free-running." Sugino replied cheekily. "Your mission is to lead and distract Karasuma-sensei by the direction of the cliff."

"While we-" Karma gestured to the three of them with a mischievous grin. "-will distract Koro-sensei by the pool."

The intuition calculated the distance before his lips quirked to a small smirk. "Ah."

"We do want to invite you to the pool, but," Nagisa and Karma shared a look. "we know you won't like it."

He nodded, warmed with the consideration. "Thank you."

"Anyway, go now." Sugino urged. "They'll be waiting by the pine tree."

He went off with a wave to them.