From *Gaku Gaku Animal Land*: Arc tries to glean what's so special about Shiki's high-school experiences by teaching his class for a day.

Renji Himuro is a man who has risen from a delinquent on the streets of Yokohama to become the young leader of Japan's largest criminal organization, the Kyowakai, with his sights set on unifying the entire Japanese underworld. One day, he receives an anonymous message. The message reads, “We are waiting for you, come alone," along with a picture of his only son all tied up. The lonely struggle of Japan's most powerful gangster begins… (Source: Young Champions Web, translated)

The victim's "proof of life" is always found at the scene. Kuzuhara Akane is a new forensic investigator assigned to the Criminal Investigation Division. As Akane strives to become a full-fledged forensic investigator, she meets Sugurishiro, a man with 12 years of experience in the same forensic investigation division who has an unrivaled fetish for bones. At the first crime scene she goes to with Suguris, they come face to face with a drowned body that has been pulled from the sea. Akane's legs freeze when she sees the Severely damaged body. However, the identity of the body that Suguris discerns is a surprising person...? Drowning, suicide, murder, lonely death. A shocking detective forensic mystery in which the truth is revealed by the last voice of the unnatural death ! Based on the story/"The Prayer of the Forensic Investigation Division: The Case Files of the Osaka Prefectural Police's "Unnatural Deaths" (Murakami Kazuo, Wakaba Bunko) Supervised by Murakami Kazuo (former Osaka Prefectural Police Inspector)