Earnest and pleasant Sada is a high school teacher popular with his students and colleagues. One day, while patrolling after school, he encounters a female student being attacked by someone with a knife. He doesn't get the chance to run away, and dies. However, Sada wakes up on a cold table.... Note: Chapters 1-5 were serialized under the title "Living Dead". The series' title changed to "Sleeping Dead" with the release of the first volume.