The suicide of a female teacher 15 years ago was actually a murder. A new investigation team, spearheaded by Mizorogi, is formed based on new information turned in to the police. Obsessed about cracking cases right up till the statute of limitation, Mizoguchi has a bitter thought about a 300 million yen case that has reached the statute of limitation... When he goes to investigate the male high school student(s) whom the woman had taught and other persons related to the deceased, he sees an unexpected connection with another case...