Tsuna accidentally punches and sends Birds flying. An angry Birds orders the Bloody Twins to kill everyone. One of the twins goes and charges at Shamal but Shamal is able to defeat him with one of his virus mosquito. Meanwhile, Lambo takes Haru to safety while I-Pin defeats the other twin. With the twins defeated, Birds tries to escape but Gokudera stops him and defeats him with one kick. Suddenly, Bianchi notices someone in the bushes and tells them to come out. That someone turns out to be Futa. Tsuna tries to approach him but Futa tells him to stop, saying that he can't go back anymore and that his following Mukuro Rokudo. Futa then leaves and Tsuna goes after him. Yamamoto and Gokudera try to go after them but finds their path blocked by another assassin.
Meanwhile, Tsuna lost sight of Futa and finds himself face to face with Mukuro. Tsuna begins to panic at the sight of a Kokuyo student but Mukuro pretends to be a hostage of his gang and thanks Tsuna for rescuing him. Tsuna is relieved, thinking that he met an honest person. Mukuro goes to ask Tsuna who is with and Tsuna tells him about Bianchi and Reborn. Mukuro pretends to be surprised and tricks Tsuna into giving him some information about Reborn. Tsuna asks him about the whereabouts of Hibari and Mukuro replies that he's confined in one of the buildings. When Tsuna asks for which building, Mukuro tells him that he is the one asking the questions. Tsuna senses something different about him and runs back to his friends. After Tsuna leaves, Chikusa Kakimoto arrives and tells Mukuro that Reborn is probably one of the Arcobaleno and Mukuro agrees, saying that since he's not joining the battle directly, he must have something up his sleeve. Chikusa notices that Mukuro is happy and Mukuro tells him that Tsuna is weaker than he expected and that they need to see what Reborn can do, thinking that he would use it against the Fake Mukuro Rokudo.
Gokudera and Yamamoto find themselves face to face with a man, carrying a huge ball and chain, who reveals himself to be Mukuro Rokudo from the picture. Gokudera begins to feel the effects of Shamal's treatment and almost collapses, causing Yamamoto to step forward and be Mukuro's opponent. Mukuro uses his Thousand Snake Fierce Domination and hits Yamamoto. Meanwhile, Tsuna is finding it difficult to return to the group while Reborn decides to use the Dying Will Bullet.
Note: Bold + Italicized = First Appearance