“I’ll perform perfectly as usual. To bring happiness to everyone with my singing.”

Diva’s daily performances on the main stage are sold out, and she has cemented her position as the indisputable AI songstress of NiaLand. She is invited to perform at the Zodiac Signs Festival, which will feature AI singers from around the world, but is pulled into a precarious situation during the rehearsal. At that moment, a cube-shaped AI that she has never seen before appears in front of her and…

“I fulfilled my promise, Diva.”

It has been five years since Vivy has returned and Diva has disappeared. Vivy is being exhibited at the AI museum, and is faced with her defect of being unable to sing. When Matsumoto appears before her again, she finds hope in taking part in the Singularity Project, but he informs her that the project has been completed.

“…What does the heart mean to you?”

“Our aim is to annihilate all of humanity.”

Based on the calculations of the Archive, the integrated AI database, humanity is now on the brink of extinction. As the countdown to human extinction begins, Vivy and Matsumoto decide to join forces with their archenemy, Toak, in order to plan a strategy to break into Arayashiki, the core of the Archive. However, Matsumoto notices a possible solution which he presents to Vivy, after she is contacted by the Archive.