Saika High School, founded in 1624, is the oldest high school in western Japan and will celebrate its 400th anniversary in 2024. Kaname Aokari, a library committee member, is reluctantly tasked with creating a website documenting the school’s history. While organizing materials, he discovers a mysterious book titled The Bizarre Crimes of Saika High, detailing past tragedies at the school.

The book reveals that three female students had been murdered, and as Aokari reads further, he finds his own name under “2024 - Kaname Aokari - Death.” Suddenly, a pale-faced boy named Saika appears, claiming, “I’m here to save you.” Aokari collapses and wakes up in the past, where he meets Chiyoko Shirakami, the first victim listed in the crime history. Saika tells him, “Saving her will save you too.”

This marks the beginning of Kaname Aokari’s journey to rewrite his fate and uncover the mysteries of Saika High School.