Katekyo Hitman Reborn!

Sawada Tsunayoshi, or Tsuna, our male protagonist, is not good at either studies nor sports. So he gets a tutor who goes by the name of Reborn. Surprisingly, he is a baby and his purpose is to shape Tsuna into the full-fledged 10th boss of the Vongole Family. Reborn teaches Tsuna via shooting him with a Deathperation bullet. Those shot by such a bullet are revived to fulfill their dying will.