Mermaid Forest

Mermaid's Scar (Part I) (1x12)

:

Yuta and Mana meet a boy, Masato, who is traveling to live with his mother. One night two years later, Masato stabs his mother in the chest, then cleans up the murder scene. The next morning, Masato's mother is alive again. The woman who runs the kitchen at a nearby construction site, where Yuta and Mana work, tells them that Masato's mother died in a boat accident, then came back to life. Later, Masato's mother notices that her chest wound isn't healing. Masato gives Yukie, the housekeeper, a piece of mermaid flesh, making her Deformed. Yuta arrives in time to kill Yukie, while Mana escapes to safety with Masato. Masato realizes Mana is immortal and tasers her. Meanwhile Masato's mother, wounded by the Deformed Yukie, tells Yuta that Masato gave her mermaid flesh after a World War II bombing raid, making her essentially his immortal captive. She ran away, but he found her again from the news about the boat accident. She finally dies. Elsewhere, Masato plans to kill Yuta.