Tsuna Sawada, who is bad at pretty much everything, is assigned a strange tutor: a baby wearing a suit who claims to be a hitman named Reborn.

Thanks to the deathperation shot, a special Vongola Family bullet, Tsuna wins his match against Mochida and is able to talk to Kyoko.

Two strangers arrive in town searching for Tsuna's house; meanwhile, Tsuna has become friends with Yamamoto and Gokudera.

Haru Miura is a girl who has been secretly watching Reborn ever since she fell in love with him at first sight; she finally makes her move, but when she talks with Reborn, she gets the impression from his words that Tsuna is a bad influence on him.

The Disciplinary Commitee has immense power in the school that Tsuna attends; school council leader and head Disciplinary Commitee member Kyoya Hibari is the leader of the delinquents, and mercilessly attacks anyone who is weak.

Tsuna is saved by I-Pin, a small child wearing Chinese clothes whose techniques can only be described as psychic powers.