Reborn is hit by Lambo's ten year bazooka and sent to the future. The strange thing is nobody came in his place. Thus Tsunayoshi Sawada tries to make Adult Lambo appear by taking Lambo's bazooka and firing it at him in order to explain what had happened, but results Tsuna to be accidentally shot in the process. He then appears in the world ten years in the future. Hayato Gokudera also appears and soon realise they are not being sent back after the usual time limit. They are then attacked by Lal Milch who is later revealed to be an ally.

Tsuna and Gokudera venture with Lal Milch in the woods. They come across a machine dangerous called a Mosca Robot. The future Takeshi Yamamoto defeats the robot and leads them into the hideout where they find out the truth and the secrets. There, Tsuna meets Reborn.

Tsuna, Gokudera and Yamamoto goes out of the hideout and to the outside. They try to find Kyoya Hibari but run into Lambo and I-pin protecting Haru Miura and Kyoko from two Millefiore Family members from Blackspell. Just as Future Takeshi Yamamoto is about to defeat them, a cloud of purple smoke appears and the past forms of Takeshi Yamamoto, Lambo, I-pin, Haru, and Kyoko appear.

Yamamoto is knocked unconscious by the Millefiore members while trying to protect everyone. Gokudera uses his ring and opens his box weapon to reveal a cannon. He defeats one of the Millefiore members. While protecting Kyoko, Tsuna manages to defeat the second Millefiore member by using his Zero Point Break Through technique.

While recovering from his injuries, Tsuna learns the only way to return to the past is to gather the guardians, defeat Byakuran and eliminate the man with the glasses, Shoichi Irie. Lal-Mirch teaches Tsuna, Yamamto, and Gokudera about the rings and boxes; The rings are revealed to emit a flame depending on the element of the user and boxes contain weapons or animals enchanted by those flames. Lal Mirch asks Tsuna to open a box of an unknown element as the sky flame is able to open boxes of all elements.

Tsuna manages to open the box given to him by Lal Mirch to reveal an Arcobaleno Pacifier, but made of stone. When the base receives a SOS signal, it is found to be from Hibird. Kyoko is also revealed to have run away from the base in search of her brother in the future.

Tsuna and Lal Mirch search for Kyoko while Gokudera and Yamamoto search for Hibird. As they are searching, Gokudera and Yamamoto encounter Gamma, one of the Six Funeral Wreaths of the Millefiore Family. Gokudera decides to fight Gamma alone without Yamamoto's assistance.

Tsuna and Lal Mirch manage to find Kyoko at the house of the future Hana Kurokawa. During the fight with Gamma, Gokudera is almost killed but saved by Yamamoto. Settling their differences, they decide to work together to defeat Gamma. Yamamoto is knocked unconscious during the battle

As Gamma is about to deliver the finishing blow to Gokudera, the future Hibari arrives to save him. Hibari manages to defeat Gamma with his hedgehog box animal and tonfas, both which are enchanted with the cloud flames.

When the battle is over, Hibari shows Tsuna and the others the entrance to his base which is also connected to the Vongola base. Once everyone returns to the Vongola secret base, Bianchi and Fuuta arrive to give new information on the Millefiore Family. They reveal the location of the Millefiore base on Japan which is under the Nanimori Station underground Shopping Mall. They decide they must train before beginning their attack on the Millefiore.

When I-Pin becomes sick, Kyoko and Haru decide that Haru should bring her to a doctor. Haru manages to sneak away from the Millefiore and visit a doctor. Haru is later noticed by one of the Millefiore members. Bianchi arrives to try and assist Haru but they both become cornered by the Millefiore member and his box weapon of bees. Tsuna later arrives and defeats the Millefiore member by using the Zero Point Breakthrough.

Lambo sneaks out of the base when Fuuta goes out to fix a loose cable. Lambo is captured by a Millefiore member who demands the location of the Vongola base. Lambo uses him to his advantage in order to get some candy. After learning of the kidnapping, Tsuna and Fuuta follow a trail of Lambo's candy and find the Millifiore member with Lambo. As Tsuna gains the upper hand in combat, the Millifiore decides to threaten Tsuna with Lambo's life. Afterwards, Hibari, annoyed by the disturbance in Nanimori, easily defeats the Millefiore member

Tsuna's training with Hibari begins. During their battle, Tsuna is trapped enclosed by Hibari's hedgehog box weapon. Hibari reveals Tsuna will die from lack of oxygen if he does not escape. Tsuna, reaching his limit, prepares one final attempt to burn through the hedgehog. He burns a small portion and realizes that small portion is where the Vongola ring was. He realizes his X-Gloves flames must be equal to the Vongola ring's flames to break through. Tsuna collapses from the lack of oxygen. Just then, Tsuna's Vongola ring emits images to Tsuna's head and reveals the past crimes of the Vongola.

Yamamoto and Gokudera begin their training. Whilst Tsuna is in the spike ball, he has a visions of all the Vongola Bosses and their past wrong doings. The bosses demand Tsuna to accept the history of the Vongola but Tsuna refuses. The first Vongola Boss, Vongola Primo, accepts Tsuna as the successor to the Vongola. Tsuna then escapes with the help of his upgraded X-Gloves which now emit the sky flames. Continuing their battle, Tsuna grabs one of Hibari's hedgehog box weapon and releases it on Hibari. Meanwhile, Chrome is shown to be inside an abandoned building.

Hibari decides to let Tsuna live, wanting to fight Tsuna when he is finished training. The history of boxes is explained thoroughly by Hibari. Whilst explaining, Bianchi is also explaining everything she knows to Gokudera. It is said that the boxes were made because of coincidence and sold at extremely low prices. There are more than three hundred designs. Meanwhile, Byakuran reveals the 7³ plan; the 7 Mare Family Rings, the 7 Arcobaleno's Pacifiers and the 7 Vongola Family Rings that will give them the ultimate power. Squad 8 is sent to investigate deaths in Japan.

In this episode, Tsuna and Yamamoto learn about Gokudera's past. It is revealed that Hayato is an illegitimate child, born of Bianchi's father, the head of their mafia family, and a famous pianist. It is revealed that she died in a car crash when Hayato is still young. Hayato doesn't find out that she was his mother until years after the crash, but when he finds out, he runs away from home. After learning Hayato's history Glo encounters the past Chrome.

Glo Xinia immediately attacks Chrome, who is in a state of panic and confusion due to suddenly being transported 10 years into the future. Just as the battle seems to be over, in Glo's favor, it is suddenly revealed that the Owl weapon that Glo has been using is actually possessed by Rokudo Mukuro.

With no escape routes available, and Mukuro Rokudo being in a weakened state, Mukuro explains to Chrome Dukuro that it is up to her to win the fight. Drawing power from both her trust in Mukuro and the Vongola Ring, Chrome's illusions become far more effective, to where even Glo can't tell whether or not they are real. The fight soon concludes in a victory for Chrome, and the future Ryohei is introduced at the very end of the episode.

Chrome is brought back by Ryohei to the Vongola Hideout, and delivers the message to the surviving Vongola family members—including the Varia—along with several Alliance families, are planning to attack the Millefiore family in just five days. With the 7 Guardians finally reassembled, it is up to Tsuna to decide whether or not they will participate in the attack.

Due to the Dellinger Phenomenon, the sun has interfered with all signals and has caused technical difficulties worldwide. Because of this, the defenses within the hideout are turned off and the setting becomes dangerous. Reborn explains a little about the Negative Tre ne Sette rays and how the Arcobaleno are affected, and he fears for Lal's life because she is a defective Arcobaleno. She seems to be affected more than Reborn. Meanwhile, Lambo and I-Pin have gotten themselves stuck inside the second power supply room and become blocked in when the backup defenses are turned on. Lambo has destroyed part of the control and the room suddenly becomes dangerously overheated. Finally, it takes Tsuna in his Dying-Will Mode to open the doors and release the children.

The incident that Lambo caused comes to an end, and Tsuna and the others begin their training again. Lal suddenly orders Tsuna to watch everyone else's training. Tsuna is confused, but first goes to Yamamoto's place. When Tsuna peeks into the training dojo to see how he is doing, he sees Reborn and Yamamoto's harsh training. Yamamoto has yet to produce results, and Reborn is treating him harshly. When Tsuna goes to the Storm Room to check up on Gokudera, only Bianchi is there…

Chrome's condition has been stabilized after Hibari tells her it is her duty to live as the Mist Guardian. She uses the Vongola Ring and creates incomplete organs, barely enough to keep her alive. Tsuna, after examining the situation, tells them the raid will begin in five days.

Tsuna apologizes to Haru and Lambo and thanks to them, figures out that behind power, is support. Tsuna tries to release a "hard flame" with "soft flame" supporting him, but fails because he can not find the balance. While unconscious after blasting into a wall, Tsuna and Chrome are sent dreams by Rokudo Mokuro of a strange white "machine".Gokudera has finally mastered the Systema C.A.I. and finding a small cat in one of the boxes.

Gokudera's kitten box weapon dashes off and Gokudera makes chase. Recaps of Goukerdera and Tsuna in the future arc starting with episode 74.

Byakuran calls Irie and tells him that Mukuro has been defeated and that he was found to be transmitting data, possibly to the Vongola Tenth. Byakuran tells Irie that he is the most important person in that base and must escape if they invade the base. Irie for some hidden reason, can't leave. Irie calls all the Milliefore Japan members in the base and tells them he shall be leading the base now. The members are outraged and prepare to attack Irie until a swordsman by the name of Genkishi tells them anyone who opposes master Irie will be killed. Irie becomes the boss of the base. Afterwards the Vongola have received the data transmitted by Mukuro. In it was the picture of the white box Tsuna saw in his dreams. Training is resumed and Reborn gives Yamamoto a box about the sword emperor.

Yamamoto watches DVDs of Squalo's battles swordsman in order to learn from them. Tsuna's training with Hibari continues, this time, he tries to use his Vongola Gloves to fire off flames. Yamamoto manages to create a tenth technique for the Shigure no Shouen Style. Yamamoto's training is complete.

Yamamoto and Gokudera have finished their training. Meanwhile, Tsuna loses his charm made by Kyoko. Later, he bumps into her and she gives him it back, then the first black spell battle is recapped. Also, Hibari reveals that the Millefiore battle simulation reveals a 0.0024% chance of success for Vongola. Thanks to Glo Xinia, Millefiore now knows where the Vongola Base is.

Tsuna and the others prepare for their attack the next day. They've been given Marmon covers on their rings which will hide them, dying will resistant clothing, and a communication system. Meanwhile the Millefiore digs their way underground and ends up at where the transmitter was. It turns out Hibari noticed the transmitter and carried it there to lure the Millefiore members away from the base.

Hibari starts knocking the Millefiore members unconscious one by one. The place he lured them to is revealed to be meant for attacks like this. The Vongola find out that one of the shopping malls ducts lead to the Millefiore base. They enter the ducts only to trigger a trap where lasers prepare to fire on them.

Tsuna and the others escape the ducts by breaking it open and falling to the ground below. There they face Dendro Chilum. Tsuna defeats him with the X Burner and they continue in the Millefiore base undetected.