Yuri, who has lost their memory, wakes up aboard the Interstellar Cruiser D.Q.O. They are taken by Setsu to participate in a meeting to identify the "Gnosia," a being that attacks and annihilates humans.

Yuri, who looped back to the first day, attends the meeting knowing who the Gnosia is. Yuri tries to cast suspicion on SQ, but the discussion doesn't progress as expected...?

Shigemichi and Stella join the group, and a meeting is held with seven people. During the meeting, Yuri uses their intuition to identify the Gnosia, but they struggle to convince the other crew members.

Despite identifying the Gnosia and surviving, Yuri finds themself back at the first day in a daze, when a person with an unusual presence, Yuriko, appears before them. She seems to know something, but...?

New crew members Comet and Chipie join the meeting. Two of the crew claim to be engineers, but Racio argues against voting for them, resulting in the votes going to...?

Yuri attends the meeting in a new role as the "Guardian Angel." With Jonas and Kukrushka joining, the meeting now has 13 people, and as the situation becomes chaotic, one crew member raises their hand.

Otome and Remnan join the crew and try to start the meeting, but another crew member, Sha-ming, won't come out of his room. Meanwhile, Shigemichi begins to talk about his feelings for Stella.

Remnan and Kukrushka announce they are on "Guard Duty," which confirms their humanity. Kukrushka is suspicious of Sha-ming, who does something in a meeting that becomes more complex as roles increase.

Yuri awakens as a Gnosia. While feeling conflicted about deceiving the crew, they remember Comet, who is in the same position. This inspires Yuri to fulfill their role as promised to Setsu.

Yuri loops again and is surprised by their new appearance. Meanwhile, the meeting is postponed due to Sha-ming's absence. Racio speaks to a now-bewildered Yuri about the secret of the silver key.

Yuri wakes up in a new world line to find that they are on "Guard Duty," alongside SQ. The two grow closer, realizing that the other is human. Eventually, SQ reveals her own "true identity."

Jina extremely dislikes lying and deceiving others. When Yuri confides in her about the loop, she recalls painful memories and expresses her fear and resistance to becoming a Gnosia.

Setsu loses consciousness before the meeting and is taken to the infirmary. While sharing the information they had gathered, Yuri suggests a change of pace to Setsu, who is showing signs of fatigue from hundreds of loops.

Yuriko tells Yuri, "If you survive this loop, I will tell you everything." They attend a meeting with all 15 crew members. However, once the meeting begins, Yuriko makes an unexpected proposal.

Yuri, an "Engineer" in this loop, identifies Racio as a Gnosia. Racio claims innocence based on a certain action. With the appearance of the "AC Follower," the meeting descends into confusion, putting Yuri in a corner.

Yuri wakes up in a world line where the ship has escaped the Gnosia contamination. Yuri is confused when Kukrushka indicates that it's the "end of the universe." Then an alarm sounds, warning the detection of an anomalous lifeform.

Yuri learns the truth: that they are a "bug" that shouldn't exist. They struggle to escape the time loop and the cosmic collapse caused by their dual existence, but...?

Before escaping from Liu-An-- Yuri wakes up on "DAY 0," the day before the day that always loops. The Setsu they encounter there seems unaware of the silver key or the time loops...?

Yuri manages to escape the time loop, but the crew members have lost all memory of Setsu. They search for traces of Setsu on the planet where they land, but are confronted with the fact that Setsu's very existence has vanished.

To end Setsu's loop, Yuri obtains Racio's "Silver Key." As Yuri attempts to wield the key again, Racio calls out to him.

Yuri is reunited with Setsu beyond the dimensional gate. They are in the first world line before Yuri received the silver key. And then, the final conversation begins…