Tsuna is destined to become the tenth generation boss of the Vongola family—a role he absolutely does not want.
At school, he's earned the brutal nickname "No Good Tsuna" for being clumsy, a poor student, and generally easy to push around. But his real problem is the mafia thing. Tsuna is deeply resistant to anything involving organized crime, constantly denying his position as a future mob boss and steering clear of anyone connected to that world. During the Future arc, he's even more blunt about it: he'd rather see the Vongola destroyed than accept its violent history. When Reborn and other mafiosos do their thing, Tsuna reacts with shock and horror—though often played for laughs.
That said, Tsuna isn't totally ungrateful. Despite his refusal to embrace the mafia life, he's genuinely thankful for the friendships he's built since Reborn showed up. His "family"—the people around him—means everything to him. He'll put himself in danger without hesitation to keep them safe, even if it goes against his whole "I don't want this" philosophy.
What's interesting is how much Tsuna mirrors Giotto, the Vongola's founder and first boss. Their personalities seem to run along similar lines, with comparable goals and moral standards. It's less coincidence and more like history repeating itself.
Content compiled by AnimeList.moe from publicly available sources.