Illusion vs. Illusion
Having found out that Chrome Dokuro is the Vongola's representative of Guardian of the Mist, Tsuna acknowledges her as a part of the family and allows her to take part in the duel. After many exerted attempts to attack 'Marmon' (now known as Viper of the indigo pacifer), Chrome eventually loses to the illusions. However, the battle does not end and an unexpected person comes in to assist in the battle.
Aired 29/09/2007EP 51 - Illusion vs. Illusion

REBORN!
Nowadays, the mafia world is ruled by Italy's strongest family, the Vongola. Vongola's current head, ninth in the row, is an old man ready for retirement. But before he can hand down his position, he needs help from a professional Hitman to prepare the next generation Boss for ruling over Vongola and the mafia world itself.
Sawada Tsunayoshi is just your ordinary teenage boy who attends Junior High and sucks at it. He is unpopular, has no friends, and is desperately in love with a girl from his class. But his life takes an extraordinary turn when Tsunayoshi meets Reborn, an infamous hitman, who the ninth boss of Vongola has sent to train Tsunayoshi for his upcoming title.
(Source: Katekyo Hitman Reborn! FC)