Episode 4 — Seto No Hanayome -

: A disciplined student and the daughter of a police officer, her presence adds a new layer of tension as she constantly monitors Nagasumi and Sun.

: Nagasumi spends much of the episode frantically protecting Sun from Mawari's attempts to splash her with water. His desperation stems from mermaid law: if Sun’s identity is exposed to a human, she or the witness must be executed. Seto no Hanayome - Episode 4

: Mawari begins to suspect Sun's true nature after she briefly glimpses Sun's mermaid tail following a water-related accident at school. : A disciplined student and the daughter of