Fearful of Yuto's fate knowing of the truth of what happens to those who aren't remembered, Ryotaro decides to try to become strong enough to protect him and time.

As Ryotaro's dread on Yuto's fate is furthered with him becoming Zeronos again, he and the Imagin try to figure a way for him to transform in the past due to the mysterious future line throwing off their synchronization.

When Kai begins a multi-tier attack in order to eliminate Airi, both Ryotaro and Yuuto try to stop him, with a Imagin deciding to help in trying to make sure that the past and future is protected...

On their way back to stop Kai from killing Airi, Urataros takes over the DenLiner with several other Imagin, dumping Ryotaro at the moment where his missing memory is revealed!

Ryotaro returns to the present to confront Kai and bring an end to his mad reign of terror, even if it means an end to all Imagin, including Momotaros and his allies!

The DenLiner breaks down and the Imagin go to Junichirou to fix it; Yuuto Sakurai and Deneb emerge to stop Sougo from obtaining an unstoppable power.

Momotaros is warned about the demon king by Yuuto, taking back the Den-O watch in the process; the gang must travel back to 2011 to stop the Mole Imagin.