Human Specimens

The bodies of six young boys are found in six cases. Shiro Sakaki, a professor considered to be Japan's leading expert on butterflies, turns himself in. He has recorded everything in a report, from his motive to the process of his creation.

Shiro starts to express his artistic viewpoint during interrogation. Meanwhile, the art camp is cancelled when Rumi falls ill. As the detective investigates further, a big mystery arises, and the interrogation gets to the crux of his story.

After creating five specimens, Shiro's final target is his son, Itaru. Despite the memories with Itaru, Shiro only sees his son as a butterfly. Shiro makes up his mind to create his last specimen.

Itaru stays home while Shiro leaves for an observation survey of butterflies. When Shiro returns, they have dinner. Shiro opens his son's computer with a strange feeling about the specimens in his room. Years later, Shiro gets a letter from Anna.

After art camp is cancelled, Anna invites the boys to the mountain house, and she insists she made the human specimen. Meanwhile, Shiro understands Itaru's motivations. The truth behind Itaru's death and the mystery of Anna's confession is revealed.