Season 1

One morning, the students (Keyakizaka 46) find their homeroom teacher, Daigoro Tokuyama (Kyusaku Shimada) dead. He is still warm. Suddenly, their sub-homeroom teacher Kanzaki (Noriko Eguchi) appears. Frightened, they hide the body. Kanzaki asks if they'd seen Tokuyama. Evading discovery, they decide not to call the police, but to keep hiding the body.

The students of Grade 3 Class C (Keyakizaka 46) receive a message from their dead homeroom teacher, Daigoro Tokuyama. They search for him and find that his cell is gone. Yurina Hirate (as herself) believes the murderer sent it. As they return the body to the locker, Hashibe, the janitor, comes to the classroom saying Tokuyama sent him a message.

The body of their dead homeroom teacher, Daigoro Tokuyama, is gone! As the perplexed students (Keyakizaka 46) peer into the empty locker, they receive another message from Tokuyama. But Tokuyama is dead; who moved him? The next day, a mysterious woman appears. She seems like she is probing for something. Does she know about the corpse? But no, she's looking for something else...

Three days since they've hidden the body of their homeroom teacher, Daigoro Tokuyama. Their sub-homeroom teacher, Kanzaki (Noriko Eguchi), takes over. The students grow suspicious about Kanzaki and each other. Suddenly, Yashiro , a detective, appears. The students are scared they've been busted, but he asks them instead about another curious incident...

The students find something hidden in the air-conditioner. Was it their homeroom teacher, Daigoro Tokuyama who hid it? As the students investigate, Detective Yashiro suddenly returns. The next day, the classroom is hot, and the body is reeking. That's when Neru Nagahama suddenly comes back to school. They interrogate her the moment the teacher leaves the room.

9 A.M. The students have gathered and are wrapping the body of Daigoro Tokuyama in tarp. They have a certain plan in mind for the night. Just then, a security guard comes in. They make an excuse for being there, and somehow make him leave. That's when they find a man peering into the classroom. Will they be able to carry out their plan?

Daigoro Tokuyama appears in the classroom! The students scream, but Yurina Hirate notices that it's a different person. His eyes are too clear, and he's too clean. "I don't think Daigoro is alive anymore," the man says. He had come to the school to investigate because Daigoro had called him about some trouble at school. So, who killed Daigoro Tokuyama?

Daishiro , Tokuyama's twin, is pretending to be Daigoro to find out what happened to his missing brother. The security guard closes in on him, demanding "the list." Meanwhile, Yurina Hirate is closing in on Yuka Sugai . Yuka was on Tokuyama's list. The students accuse her of killing him to hide the secret of the list, but...

6 days since Tokuyama died. Tomorrow is the school festival. Class C is doing a haunted house. They consider using Tokuyama's corpse for the event. Just then, the new principal Kazusa Midozono comes in. The students are alarmed that the former principal Sangubashi has suddenly quit. Midozono asks about Tokuyama since something strange was written in his planner.

As they prepare for the school festival, three graduates of Keyaki Private High come looking for Tokuyama to invite him to their reunion. Yurina Hirate tells them he's absent, but they don't believe her since they just received a message from him saying he's in the classroom. Just then, Kanzaki comes in, and for some reason, the graduates are surprised.

The evening before the school festival, the janitor Hashibe shows Yurina Hirate a DVD. Neru Nagahama takes it, just to see that it's been broken. It's the confiscated DVD that Tokuyama gave to her the day he was killed. The class had watched it before, but they'd seen nothing suspicious. Who did it? Meanwhile, they find out who'd been sending the messages.

The day of the school festival. The students are tired from the preparations and have fallen asleep. They give up trying to make it in time, and cancel their haunted house. Then, as someone comes in, numerous "ghosts" appear and surround the person. One ghost reveals herself to be Yurina Hirate, and she unravels the mystery of Tokuyama's death. So, who killed Daigoro Tokuyama?