Tsuna is a hapless youth with low test scores and lower self esteem. His mother hires a tutor to help Tsuna out, but it comes as a surprise to the both of them when the tutor is a baby named
Reborn, claiming to be from the Mafia. Reborn informs Tsuna that he’s the next heir to the Vongola family mafia family and tries to help Tsuna reach the goal. Reborn possesses the Dying Will bullet, which kills a person and brings them back to life to fulfill the last regret they had, and even works to get Tsuna some henchmen to make him a true mafia boss-in-training.
The mafia underworld is ruled by the strongest people in the business, the Italian Vongola family. Vongola’s current head, the ninth head, is an old man ready for retirement. But before he can step down, he needs help from a professional hitman to prepare the next next head of the family for the world that awaits him.
Sawada Tsunayoshi is an ordinary teenage boy who attends Junior High, who is unpopular, has no friends and is desperately in love with a girl from his class. But Tsunayoshi’s life takes an extraordinary turn when he meets Reborn, an infamous hitman, who has been sent by the Vongola boss to prepare Tsunayoshi for his future as a mafia boss!
Middle school student Tsuna has always gone through life in last place; but when he learns that he is getting a tutor to help him raise his game, he had no idea that his benefactor would turn out to be… an infant and a mafia hitman?! As if things can’t get much stranger, Tsuna then discovers that the powerful Vongola family has chosen him to be its next successor – a position that has control over all mafia families. Joined by friends Tsuna unwillingly starts out on his path to becoming a mafia boss – if he can survive the training!