Tachioni, also known as "The Bull," is one of the members of the Wolf Pack gang. Among the members of the Wolf Pack, he is the most short-tempered. He and Romeo fought repeatedly with each other. Their famous fight is the one that happened during the Black Brothers—Wolf Pack showdown at Sempione Park.

Before the showdown began at the park, Giovanni, the leader of the Wolf Pack, said that weapons are not allowed in the fight, but Tachioni still cheated. He drew a blade and tried to kill Romeo. The Wolf Pack was defeated by the Black Brothers because of Tachioni's cheating.
In the last episode, Tachioni and the rest of the members of the Wolf Pack gang made peace with the Black Brothers.