Human Specimens

In midsummer, bodies of young boys are found in six acrylic cases in the mountains; Shiro Sakakil, 50, a university professor and Japan's leading butterfly expert, turns himself in.

Shiro passionately expresses his artistic viewpoint, but the art camp is canceled due to Rumi's worsening condition; he returns to the mountain to take the boys home, where six acrylic cases are on display in the warehouse.

After creating five specimens, Shiro's final target is his beloved 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; the story shifts to a new perspective.

Itaru stays home while Shiro leaves for an observation survey; Itaru stares at the specimens and invites his friends; Shiro opens his son's computer with a strange feeling about the specimens; three years later, Shiro receives a letter from Anna.

Anna seemed proud, but longed for a successor while looking at her mother, in the spotlight; she insists she made the Human Specimen; the truth of Itaru's death and the mystery of Anna's confession unravels.