Mafia Land is at war with the Carcassa Famiglia led by Skull. Tsuna and Longchamp ask Reborn and Colonello what to do but the two suddenly falls asleep. Meanwhile, at the Carcassa ship, Skull orders his troops to disembark and annihilate the people on the island within one hour. Tsuna and Longchamp decides to leave the training grounds and ends up in front of the Mafia Fort. The two enter and is welcomed by Mangusta, Bianchi, I-Pin, Nana and Lambo. Tsuna is surprised that his mother is acting just like Yamamoto and watches her and Bianchi leave to help with the food. Tsuna hears that Longchamp informs the Mafia Families that he let the spy in and is surprised to see that all the men are complimenting him and are happily preparing to fight the Carcassa Famiglia. The families starts to argue about who would lead the war but Gokudera informs everyone that Tsuna is the tenth Vongola Boss which causes them to pick him as the leader, much to Tsuna's dismay.
The men carried Tsuna to the front line as the enemies begin to close in. Gokudera helps defeat enemies with his dynamites while Tsuna cowers behind him. Tsuna is then carried outside where he meets Skull. One of the men reveals to Tsuna that Skull is the leader and one of the seven Arcobalenos. The men tries to shoot Skull with his bullet but Skull easily deflects it and calls his Armored Octopus. The octopus easily defeats Family members and is about to attack Tsuna when Reborn arrives and confronts Skull. He tries to talk to Skull but Skull is stubborn and orders his octopus to capture Reborn. Reborn tries to attack with his gun but Skull easily deflects it and orders the octopus to crush him. However, the octopus is surprised to see that Skull's left hand is inflating and lets go of Reborn. Tsuna then realizes that Reborn shot Skull with a Dying Will Bullet which was the cause of his inflating hand. Reborn then attacks Skull and informs him that Colonello is awake and is defeating his men. With the fight finished, Tsuna and Gokudera try to enjoy their vacation but end up disappointed when they are informed that they are going home...
Note: Bold + Italicized = First Appearance