暗殺教室 16 [Ansatsu Kyōshitsu 16]

This volume shifts into a backstory-centered reveal about Koro Sensei, explaining his origin, past identity, and the events that led him to become Class 3-E’s teacher and target. The story fills in long-held mysteries while connecting his history to the looming threat against Earth.

As the revelations unfold, the class learns more about the people and experiments that shaped him, along with the emotional ties that influenced his choice to teach. The volume emphasizes how his past reframes his motives, character, and relationship with the students.

The new information creates a major moral split in the class: some students still want to carry out the assassination, while others begin to consider saving him instead. The volume ends by setting up the next stage of the series around that unresolved choice.