REBORN! (2006) : 5x147

Tsuna returns home after completing the trial. The next day, Tsuna receives a letter from the Arcobaleno, Fong, who is also revealed to be I-pin's Martial Arts sensei. The letter tells Tsuna and his guardians to search for him around town. Tsuna, Lambo, and Haru find Fong at Namimori Middle School. Fong's trial is revealed to test Tsuna of his leadership capabilities. Tsuna is required to catch Fon in one hour by using the people at his disposal. Fong is eventually caught by Tsuna with the help of I-pin who had been hiding in the shadows, and passes the trial. I-pin, having spotted Hibari, becomes embarrassed and activates her Pinzu Time Bomb and is thrown out the window before exploding.