A sinister game begins when a group of classmates reunites at their high school reunion, only to uncover a time capsule containing a defaced graduation album—and soon, their peers start dying mysteriously. As two former classmates race to unravel the truth behind the deaths, their own hidden secrets threaten to expose a web of lies, turning every classmate into a suspect in a nonstop suspense-driven mystery: who is the true culprit?

Asagao (Juri Ueno) is a rookie forensic scientist, who works at a university forensic medicine class in Kanagawa Prefecture. She is a licensed doctor and respected by those around her. Asagao lives with her father Taira (Saburo Tokito), who is a veteran detective. Asago's mother died in the 2011 Tohoku earthquake disaster and her mother’s body was never found.

One day, Asagao’s forensic medicine class unexpectedly works with the investigation section of the police department. When a dead body is found, the dead body is transferred to Asagao’s forensic medicine class. Asagao now works with her detective father.