Tsuna is seven-years-old when he first hears rumors about Hibari Kyouya. "He's a monster," they say. "He'll even kick kittens!" a girl adds. He's not sure they're true, but one thing he knows for sure is that a) Hibari Kyouya exists and b) he likes violence. A lot.

He learns this when he is backed up against a wall, Shinji looming over him. "Lunch money," Shinji orders, thrusting a hand out. "Come on, Dame-Tsuna, I know you have some spare change. Give it here, or else." Tsuna squeaks and murmurs incomprehensibly. "Ha? What did you say?"

"I don't have any!" he sniffles. Earnest brown eyes glimmer with unshed tears as he says, "I forgot it on the kitchen table this morning, I don't have any money!"

"I know you're lying, don't make me sic Hibari on you!"

"H-Hibari?"

Shinji sneers unpleasantly. "Don't you know? He punishes people who break the rules. All I have to do is tip him off about you disturbing the peace and boom! You're a dead man walking. You'll be bitten to death! And no one can save you since everybody's scared of him." He looks remarkably pleased about his genius plan, rubbing his hands together like a stereotypical villain.

"But I'm not doing anything!" Tsuna protests weakly.

"You're infecting Namimori with your patheticness, that's reason enough. And I heard that Hibari hates stuff like that. Anyways, lunch money! Give!"

Tsuna frantically looks around for an escape route, but to no avail. Shinji looks about ready to sock him on the face so he doubts that he can talk it out. Well, Tsuna reasons, if it works for him..? He clenches a fist, stops his legs from shaking, and looks at Shinji straight in the eyes. Unbeknownst to Tsuna, orange flickers in his eyes as he thinks, I'm tired of being scared! and leaps forward to attack.

By biting Shinji on the shoulder.

XXXXXXXXXX

"Man, what's up with your shoulder?" Mochida asks, punching Shinji lightly. "Did a rabid squirrel get you?"

"I don't want to talk about it," Shinji replies sourly.

XXXXXXXXXX

Tsuna discovers that biting people is an amazing way to stop people from picking on him. They tend to steer clear of him nowadays, and it feels good. It's a bit lonely, he supposes, but he's used to it. He bares his teeth at Shinji who flinches as he passes by.

Yeah. Life is good.

Meanwhile, the teachers at Namimori are panicking and asking themselves how Dame-Tsuna became so...vicious. "He was always useless, but at least he was respectful!" the principal moans, throwing his hands up in despair. "Now, it's like...it's like he's being possessed by a demon!"

"Should we call a priest?" Nezu asks anxiously, being a victim of Tsuna's teeth. The principal gives a helpless shrug. The secretary nods solemnly and picks up the phone.

Needless to say, Tsuna did not appreciate being drenched by holy water. The priest got 400 yen and a bite to his arm for his troubles. He also got a trip to the hospital.

(He had to get thirteen stitches.)

XXXXXXXXXXX

Tsuna lets out a little sigh as he is cornered by a group of older kids. "People say that you're scary," says one, peering at Tsuna. "But we know better! You're still weak, pathetic, and spineless. And I know we can take you on." He regards the bully with blank eyes. "Don't stare at me like that, weirdo! Get him, guys-agh! Get off my arm, you little freak. Get off, get off, get off!"

Tsuna latches his jaw tight around the appendage, refusing to let go. The familiar taste of blood fills his mouth as the boy hollers. The rest of the group are staring at them, slack-jawed.

"Why are you herbivores crowding?" a voice interrupts. Tsuna looks up to see gray eyes observing him quietly. "...What are you doing."

"Mhating dem to dahs," Tsuna says into skin. He lets go as the arm suddenly goes slack. "I think he fainted."

"You better sleep with one eye open, we'll get you for this!" The group plus an unconscious boy zooms away like fire is licking at their heels.

"Not bad," the boy says with approval laced in his words. Not that Tsuna notices, because the first thing he notices are tonfas hidden inside the boy's jacket and his intuition blaring danger.

He does the first thing that comes into this mind.

"Herbivore, if you don't get off me, I will bite you to death."

"Herbivore, my arm is bleeding."

"...Did you just fall asleep?"

A/N: Prompt from Tumblr by katekyo-hitman-aus. I'll mark this as complete for now, but don't be surprised if I add on to this.