Varia Arc

On a day out having fun, Tsuna and his friends come across a boy using the Dying Will Flame and is being attacked by a swordsman, but when they try to help, they prove to be no match for him.

Dino manages to fend off the swordsman, Squalo, and explains the situation: a subgroup of the Vongola Family called The Varia is after the Vongola Rings which are held by the leading members of the family, which he then proceeds to give to Tsuna and six other people. They have ten days to train in order to become strong enough to fight off The Varia. Meanwhile, Tsuna's father returns.

Tsuna and the other six members chosen to hold one of the 7 half rings, all start to train, in preparation to face The Varia. Some even get themselves their own home tutors. Meanwhile Tsuna is told that besides him the First Vongola also used gloves, and he will soon find out who the two others with the ring are.

All of them are going through training by their respective tutors. Tsuna is being trained by Reborn, Yamamoto by his father, Gokudera by Dr. Shamal, Ryohei by Colonello and Hibari by Dino.

Under Reborn's instruction, Tsuna embarks on a search to find the missing Lambo. At the same time, Haru is testing Tsuna to find out whether he is still the kind and compassionate Tsuna who had saved her in the river.

A Vongola weapon alteration expert shows up to improve everyone's weapon. Meanwhile, two men appear, aiming to assassinate Tsuna.

All of the selected one are forced to battle against each other who have the same type of rings.

Lussuria and Ryohei fight in a heavily lighted boxing arena. Ryohei is being beaten severely by Lussuria but then Ryohei remembers his sister and the reason he became a boxer. He then gets back up ready to fight.

Ryohei continues his fight with Lussuria. When the battle seems to favour Lussuria, Kyoko & Hana appear and give Ryohei the support he needs to release his Extreme Sun Maximum Canon. Later, Tsuna wonders if Lambo can really fight in the next round. Tsuna then talks with Lambo from 10 years later who tells him not to let 5 year old Lambo use the 10 year Bazooka, for Adult Lambo may be from a future parallel world.

Lambo's fight versus Levi A. Than of Varia. As a 5‑year-old and a 15‑year-old, he stands no chance to the "Levi Volta" attack of Levi. However, when the 15‑year-old Lambo used the 10-year bazooka, Lambo from 20 years later appears. The 25-year-old defeats Leviathan with relative ease using his "Elettrico reverse" and "Elettrico Cornata" techniques, but the 5-minute limit of the 10 Year Bazooka ended, and Lambo reverted to his 5-year-old form. Just as Leviathan is about to severely injure Lambo, Tsuna stops the match in Hyper Dying Will Mode, surprising everyone.