Choice Arc

Bianchi takes Kyoko and Haru to the Vongola base while leaving Tsuna and his guardians to discuss the upcoming battles with Shoichi. Byakuran sends a holographic image stating he wants to have an official battle between the Vongola and the Milliefiore in a battle of Choice. He reveals to Irie that the Funeral Wreaths and the mare rings they wielded were fakes and he had gathered the Real Six Funeral Wreaths in secret from Irie as he had expected the betrayal. Byakuran then activates the teleportation system in the Merone base transporting all but the White Round Machine, and Tsuna along with his friends. Irie reveals that since they have completed the Arcobaleno trials, Tsuna's guardians are given their respective Vongola boxes for the upcoming battle.

After a long discussion, it is decided Tsuna and his friends rest for the first few days before commencing training for the battle of Choice in ten days time. At the Vongola base, a ring signature was caught on radar and Tsuna and his friends investigate. Tsuna and his friends find Basil from ten years ago to be the cause. At the Vongola base, Basil explains he was sent to the future ten days ago and was given a ring, a box weapon, and a book containing information about his situation and orders to assist Tsuna and his friends.

Tsuna and his friends split up and explore the Namimori of the future. They all coincidentally meet in front of their school, Namimori Middle, and relax in their classroom. Tsuna realizes that to return to their own time, they must defeat Byakuran in the battle of choice. On the roof of Namimori Middle, Hibari encounters the future Dino who insists on training him.

Kyoko and Haru become concerned that Chrome has not been eating, since she is not used to the kindness of others. Hoping to cheer her up, Tsuna attempts to find out more information on Mukuro's whereabouts from Irie, but to no avail. During a welcome party for Basil, I-pin sneaks off into Chrome's room and manages to get her to eat some gyoza. The next day, Kyoko and Haru find Chrome helping out with the dishes, and they start to become good friends.

Gokudera brings a newspaper from the current time from which Yamamoto learns about Namimori Middle's baseball team's consecutive losing streak and how the baseball club may be canceled. He heads to Namimori middle and runs into three first year members of the baseball club and offers to train them for the upcoming game. The next day, Tsuna and his friends watch the game. Namimori middle baseball team becomes discouraged as the mercy rule will be imposed if they can not gain a point. The batter, being one of the three trained by Yamamoto, remembers he should do his best for friends, and hits a home run. Yamamoto feeling satisfied with the team's progress, promises to help Tsuna defeat Byakuran.

Gokudera brings a newspaper from the current time from which Yamamoto learns about Namimori Middle's baseball team's consecutive losing streak and how the baseball club may be canceled. He heads to Namimori middle and runs into three first year members of the baseball club and offers to train them for the upcoming game. The next day, Tsuna and his friends watch the game. Namimori middle baseball team becomes discouraged as the mercy rule will be imposed if they can not gain a point. The batter, being one of the three trained by Yamamoto, remembers he should do his best for friends, and hits a home run. Yamamoto feeling satisfied with the team's progress, promises to help Tsuna defeat Byakuran.

Reborn tells Tsuna and his friends that they must master the airbikes before the Battle of Choice. While Tsuna's friends have quickly mastered the airbikes, Tsuna has yet to grasp the basic. While talking to Kyoko and Haru, Tsuna realizes he must learn how to ride the airbike one step at a time and continue to practice. With the help of his friends, Tsuna is able to grasp how to ride the airbike.

After they finished practicing on the airbikes, Reborn tells Tsuna and his friends they shall train tomorrow on opening their respective Vongola Boxes. Tsuna's box weapon shakes violently that evening and Tsuna opens it and releases his box weapon. Tsuna's box weapon attacks him and with the help of Yamamoto and Basil, they are able to seal the box weapon back to its box. Dino arrives and tells Tsuna his box weapon attacked him because he opened it incorrectly and comments that the Sky Box Weapons must be used delicately.

Dino in his room unleashes his box weapon but is accidentally swallowed by it. One by one, Tsuna's friends are swallowed by the box weapon until Tsuna and Basil are the only ones who remain. Tsuna contemplates to destroy the box weapon to stop the menace but hesitates when he realizes his friends will die with it. The box weapon begins to lay eggs and inside are Tsuna's friends who has been eaten by the box weapon. Dino reveals that the box weapon he bought rejuvenates those that it eats. Reborn tells Tsuna and his friends that they will begin to train with their Vongola Boxes.

Dino gives each of the Vongola guardians individual training regimes for their Vongola Boxes. Unbeknownst to them however, Haru and Kyoko had eavesdropped on their conversation. Lambo manages to open his Vongola Box, but Tsuna still has trouble controlling his. Meanwhile, Squalo travels to Japan.