Chapter Text
In the year 2001, dungeons started appearing on earth, bringing with them ferocious monsters and strange new powers. Hunters started emerging from humanity, pushing back against the beasts that threatened mankind and ushering a new age for the world.
Fifty years later, Sawada Tsunayoshi decides to peacefully retire after his pretty successful but mostly unremarkable career as a B-Rank Hunter.
The next day, he wakes up in his seven-year-old body, and promptly throws up.
-o-
Tsuna never knew that being thirteen again could be so peaceful. And less painful. Tsuna hadn’t been aware of how much damage his body had accumulated throughout the years until he was blessedly free of all the aches and pains. He could squat now! He could bend over! He could raise his arms above his head without his body attempting a munity!
He was also, without a doubt, much healthier and fitter than he was the first time he was thirteen due to the three full years of paranoid preparation he underwent in hopes of lessening the casualties of the first dungeon outbreak. Namimori had been the few areas that had been affected by the first wave and sustained incredible damage. It fared better than most of the other places though, due to the force of nature known as Hibari Kyouya, but things still had been quite bad.
His mother had been in the marketplace when the monsters broke out. Her legs never truly healed.
However, it was now the year 2004 and nothing had happened. Tsuna was beginning to truly believe that he had experienced dimensional travel instead of regression. It would have been nice to know that before he had conditioned himself into his current habits, but things could have been worse.
The morning started out the same as any other with his daily jog around the neighborhood. He shared training tips and gossip with Sasagawa Ryohei, a friendly senior of his, for the fifteen minutes their jogging routes overlapped. Since it was a Thursday, he stopped by the marketplace to get some groceries. He politely but genuinely greeted everyone (still invigorated by the fact that they were all still alive and kicking) and helped deliver breakfast ramen to the friendly antique store owner along his path (a business partner of his in another life who somehow looked exactly the same as he had on the day of Tsuna’s retirement?? Tsuna chalked that up to dimensional differences because how else could he explain it?).
Tsuna reached home just in time for a quick shower and breakfast. Before he left, his mother mentioned receiving a strange flyer in the mail for a home tutor and asked if Tsuna was interested. Tsuna told her that he would think about it (despite not being interested at all) and discuss it with her when he got back from class.
His mother handed him the flyer and he stuffed it into his pocket without much thought. There was going to be a basketball game today, and Tsuna had to adjust his condition and mindset to ensure that he played well enough to contribute to the team, yet not too well, lest he get accosted by the basketball team again.
That had been a rough few weeks.
Tsuna had no interest in sports or other club life. He had a part-time job at the antique store and was planning to save up enough money to trade in stocks or invest in things (he had a powerful intuition/prediction ability that seemed to carry over from his past life) so he could retire by his late thirties or early forties.
After a fruitful gossip session with his classmates as they carried out their cleaning duties (apparently Mochida Kensuke was planning to confess to Sasagawa Kyouko soon, which was a juicy piece of information Tsuna wasn’t going to share with his jogging buddy), Tsuna leisurely made his way home. Today was his day off and he was planning to spend it doing some research at the local library.
As he made a mental list of the books he was going to check out, he had the strangest feeling that he was forgetting something. Ah well. It’ll come back to him in due time.
-o-
Tsuna opened the door and his brain blanked. There was a baby in the doorway, standing upright in a three-piece suit and a fedora. He had a chameleon on his head and was carrying a baby-sized suitcase. A yellow pacifier was strung around his neck. And while all these were surreal enough to fry a mind, the absolute worst part of the situation was that Tsuna knew exactly who he was.
“Ciaossu, I’m Reborn, the home tutor.”
Why in the world was the famous and deadly SSS-Class Hunter Reborn standing on his front porch?!
-o-
“I’m here to make you a mafia boss,” Reborn said with utmost seriousness.
“Okay,” Tsuna replied, still hung up on the fact that (1) solo SSS-Class Hunter Reborn of Arcobaleno fame was sitting in his childhood bedroom and (2) he was a fucking baby.
Why was he a baby? Weren’t the Arcobaleno babies due to some dungeon curse? And how were his sideburns so curly?
“You’re taking this rather well,” Reborn mused, taking a sip of espresso from a cup that looked obscenely expensive which, where the hell had he gotten that from?
“I’m not, actually. I’m still in shock,” Tsuna replied honestly. “Also, I don’t think I can accept this offer. I have a twenty year plan and being a mafia boss is not conducive towards it.” Now that Tsuna was recovering a little from the shock, he had enough brainpower to remember that mafia bosses do not retire in their thirties unless it was due to death. Working until you died. Chilling. Tsuna wanted no part of that.
“You don’t have a choice. The current head of the Vongola Familia has chosen you to be the heir.”
And Tsuna’s brain was immediately punted back into shock town. Vongola? Top fucking guild Vongola? A mafia family? A mafia family that wanted him to be their next boss?
Now that he thought about it, Vongola being a mafia family did explain how they could shoot up the guild rankings so quickly. The part about him being chosen as heir still had yet to be explained though! Didn’t Vongola already have three (four?) heirs? Tsuna remembered there being some kind of family drama during the founding (which, in hindsight, was probably the legalizing) of the guild.
“You must be wondering how you ended up as the heir,” Reborn said. Tsuna nodded slowly. Reborn placed three photos in front of him, each depicting some sort of horrible gruesome murder scene. Except for the last one, which was just bone. Having been a Hunter, Tsuna was no stranger to gory dead bodies and instead leaned forward to identify the people in the photos. Hey, weren’t they—
“The first and most qualified heir, Enrico,” Reborn pointed to the first picture, “was shot in a feud. The second heir, Massimo, drowned. The third and favorite child, Federico, was found reduced to bone. Therefore, the only candidate left is you.”
Tsuna was going to get a concussion due to the amount of times he had been hit over the head with the shock baton. Enrico, Massimo and Federico had been the Vongola Big Three, managing to maintain the Vongola Guild’s spot as top guild for over fifty fucking years in a row through their smarts, strength, and charisma, and were still going strong on the day of Tsuna’s retirement despite all the assassination attempts, governmental pressure, world-ending catastrophes, and countless other unimaginable things they would have faced in Tsuna’s first life. There was absolutely no way they could have died to something as simple and pathetic as a feud or a drowning. Or whatever that third thing was. There was definitely more to this that Reborn wasn’t sharing with him. Besides, wasn’t there a fourth candidate? Tsuna remembered him leaving Vongola to establish his own guild, which later still affiliated itself with Vongola anyway because all roads led to Rome, or whatever Italian town Vongola originated from. Without the Big Three, shouldn’t he be the obvious pick over some Japanese thirteen-year-old who didn’t even know Italian?
(Supposedly, anyway. Truthfully, Tsuna was pretty fluent in Italian. He had to be, considering a good portion of the top ten guilds were Italian in origin.)
The gears in Tsuna’s brain began to turn, as he half-heartedly listened to Reborn talk about how his family line was related to Vongola, and Tsuna suddenly understood what was going on. He was being used as a shield.
With only one heir left, it would make sense for Vongola to keep him safe in secrecy. Meanwhile, they would find some distant relative to take on the aggro of whatever had caused the deaths of the Vongola Big Three as they carried out their own investigations. Reborn being sent as a supposed “tutor” was now understandable as well. Who in their right mind would send an unaffiliated assassin to groom the next mafia boss? However, if the assassin was sent to locate and kill the responsible parties under the guise of being a bodyguard and a tutor… As expected of Vongola. With such a foundation, it was no wonder they were able to maintain their ranking and reputation as the world’s strongest guild.
This also confirmed the death of Tsuna’s father, because why else would Tsuna be chosen when an adult man would be more convincing in the role?
The obvious choice was for Tsuna to accept this smoking gun. Not only would he have some semblance of protection from (SSS-Class Hunter!) Reborn (of Arcobaleno fame!), but he would have more knowledge, and hence more control, over the situation.
It was better to be stabbed from the front than to be stabbed from the back.
The only question was, how would a thirteen-year-old kid accept this sort of thing? Tsuna, the sixty-year-old man at heart, was at a loss. Excitement in the belief that it was all a game? Delayed fear at the danger? Some secret third thing that Tsuna could barely hope to comprehend?
Reborn was still staring at him with those unnervingly analytical black eyes. Whatever reaction Tsuna was planning to show would definitely be clocked as fake.
Unless.
“Alright then,” Tsuna said. “But you can’t interfere with my part-time job or my twenty-year plan. If you need me on the days of my part-time job, I need to be informed at least a day in advance so I can apply for leave.”
Reborn hummed. “Agreed.”
Tsuna nodded and stood up to leave the room. As he opened the door, he muttered, “Never had a dream so realistic yet so surreal before.”
“This isn’t a dream,” Reborn said.
“Sure,” Tsuna replied, and left for the library.
-o-
“Where are you going?” Reborn asked.
“Library,” Tsuna replied. “I think it’ll be interesting.”
“I already said that this isn’t a dream.” There was a hint of aggravation in Reborn’s voice.
“Okay,” Tsuna said dismissively, and then was instantly kicked into an alleyway. He twisted his body to soften his landing as he let out yowl of pain. “What the fuck?” Panic seeped into his voice. “This isn’t a dream?”
There was a familiar-unfamiliar click and Tsuna looked up to see the barrel of a gun. He froze, eyes going wide. This time he didn’t need to pretend to feel scared.
“Understand now?” Reborn sneered. It was intimidating, but not as much as it could have been. Tsuna was regaining his cool and he looked down at the ground, not wanting to show Reborn his face.
He remained silent.
Reborn seemed pleased with that reaction and kept his gun. There was some noise at the entrance of the alleyway. Neither of them paid it any mind.
Tsuna got up to his feet, mouth a thin and flattened line as he tried his best to channel the fear and paranoia he had felt during the first three years of his dimensional time travel. It wasn’t hard, because Tsuna was always feeling varying levels of that particular emotional cocktail every day of his life.
Deep in thought on the next step of his acting ruse, Tsuna bumped into someone as he exited the alleyway. He looked up to see Sasagawa Kyouko and Mochida Kensuke. Kyouko looked extremely awkward while Mochida was glaring at Tsuna in humiliation. The flowers in his right hand were wilting due to the intensity of his death grip.
Oh shit, was the confession supposed to be today?
Tsuna immediately took ten steps back into the alleyway and waved his hands forward, gesturing for Mochida to continue. They continued to stare at him.
“Just treat me as if I was never there,” Tsuna said, and then made absolutely no movement to leave the situation because this was super interesting. His worries were flung out of his mind, completely replaced with the nosiness of bored and gossipy uncles with way too much time on their hands.
After an incredibly awkward silence (though not for Tsuna), Kyouko turned back to Mochida and forced out a smile.
“I’m sorry, Mochida-senpai, but I just don’t see you that way. Can we still be friends?”
It was now Mochida’s turn to force out a smile. “Y-yeah, of course. We can still be friends.”
Kyouko bowed towards him and hurried off. Mochida silently stared at her back until he felt a hand on his shoulder. He jumped.
“Cheer up, Mochida-senpai! There’s a lot of fish in the sea. But also, it’s not good for teenagers to engage in high school romance. This is the time where we should be focused on studying and getting good grades so we can get into a good University!”
Tsuna ate a face full of flowers as Mochida stomped off. He frowned as he spat the petals out of his mouth.
“Was it something I said?” Tsuna looked at Reborn only to see Reborn give him a look of disgust before toddling off as well.
Tsuna suppressed a smile, placed his hands in his pockets, and ambled towards the library.
-o-
Reborn did not know what he had been expecting when he received Sawada Tsunayoshi’s file. A quiet, underachieving and withdrawn boy suddenly underwent a massive change sometime during the age of seven and began exercising in a near-worrying intensity. He became even more withdrawn and quiet, though his grade improved from failing to below average, and he started helping out his mother with household chores.
The first chore he took over was grocery shopping. Sawada Nana had never stepped foot into the marketplace after that, though it wasn’t for lack of trying. However, every time Sawada Nana tried to go to the marketplace, Tsuna would react badly, and eventually she relinquished grocery shopping to her son. No one could find out the reason for this sudden change.
At the age of ten, Sawada Tsunayoshi toned down the intensity of his exercise and started to open up to his classmates, engaging in more social behaviors. He even found a part-time job, which Reborn wasn’t even sure was legal.
His observation of Sawada Tsunayoshi started with him getting up before dawn and running 10km. This was part of his routine as it was noted that he would run anywhere between 10km and 20km every morning without fail. He then observed Sawada Tsunayoshi in school, where he showed the attitude of a teenage boy uninterested in class. He gossiped with his classmates, carried out classroom chores and headed home. All in all, an average teenage boy. It wouldn’t be easy to turn him into a mafia boss, but it wouldn’t be hard either. On all accounts it should be an easy job.
Then Reborn showed up on the Sawada Household’s doorstep and saw recognition in Sawada Tsunayoshi’s eyes, and things got immensely more complicated.