A young girl wakes up in what she guesses is a train and, through recalling her memories, introduces herself as Lorde Yamasaki, the Ultimate Voice Actress. She decides to explore and finds 7 others, also stuck there.
After a while, a man comes in on the monitors and introduces himself as simply the Conductor. He tells them that they are from there on out stuck in a killing game.
Joan Takei, the Ultimate Violinist, protests this, leading to her almost execution. Everyone panics at the thought of death, but ultimately just goes to bed.
When everyone regroups, Joan and Ichidou Miyaharanote tell everyone that they searched everyones' rooms, prompting the still paranoid Tsukisae to storm off. Daidai Hirota note reports that she found a heavy box, but didn't try opening it out of fear. Joan orders her to open it anyway, discovering it empty. Chouya uses the opportunity afterward to unite the group, with Lorde and Poruka Matsushima note back him up, leading everyone sans Nao Machi note and Tsukisae, en absentia, to trust each other.
The next day is rather uneventful, except for Chouya's new role as leader and Tsukisae confiding in Lorde that she was abused at home.
The next morning, Lorde, Joan, and Ichidou meet up together. Joan apologizes for her behavior, as she was a fair bit rude. This is interrupted by the discovery of Chouya's corpse.
Lorde and Daidai investigate, uncovering clues in the trial and figuring out the culprit: Tsukisae Adachi. Poruka adamantly defends her, only to realize she knew the final piece of evidence left to incriminate her: the window of time necessary to steal the weapon. After a tearful and very sorrowful goodbye, Tsukisae Adachi is executed.
Lorde wakes up and very reluctantly goes to breakfast. Poruka and Nao don't show up out of grief and anger respectively. After a re-check of the train cars, Nao appears and gives Lorde a notebook that contains a note left by Chouya. In it, he apologizes for dying and looking like a traitor. Lorde, struck by grief, falls silent, making Joan read the rest of the book. The rest has a history of Hope's Peak.
The next day is slow and tiring. Daidai has to pull Lorde out of bed. Nothing of note happens other than everyone's grief.
The next morning, everyone finds a motive note. Poruka takes them and claims to dispose of them. After some free time, Daidai, Lorde, and Poruka eat dinner together and go to bed. Poruka acts suspiciously but otherwise does nothing.
Lorde wakes up to nobody. She goes to the breakfast meeting, only to discover Poruka's corpse.
Through a very vague investigation, Lorde and Daidai piece together clues. The trial starts with clearing alibis, leaving two people without one: Joan and Nao. Joan is disputed after Daidai remembers finding Joan walking down the hall clean of blood.
Nao puts up a big fight when defending himself. He somehow makes Lorde snap before being voted guilty and being executed. Before his execution, he mentions that the cars the others had assumed were locked due to Chouya's word were unlocked.
Everyone investigates the train cars now unlocked. They discover the portraits of the classmates they assumed were dead, confirming their fears. They also find pictures of themselves with friends, including the dead classmates, in a box. Ichidou suggests sleeping then, and they go to bed.
The next day, they search the picture frames. There, they find a newspaper clipping the Conductor (whose name is apparently Josui Eguchi) did not know about. This makes him come out of his hiding place long enough for Daidai to go there in his place, going over the intercom. Joan and Ichidou hold Josui back as Lorde and Daidai press the button to execute him.
After a few minutes of crying, Daidai stops the train and the survivors step off.
