Seto no Hanayome

Michishio Nagasumi leads a remarkably ordinary life. During a summer break, he nearly drowns in the sea, only to be rescued by the charming mermaid Seto San. Seto belongs to a yakuza‑style mermaid clan, whose strict code dictates that if a human sees a mermaid, either the human or the mermaid must die. The only way to avoid this fatal outcome is for Nagasumi to be adopted into the family and marry San. In an effort to protect both of them, Nagasumi proposes marriage to San. What began as a simple summer vacation quickly turns into a complex adventure, as Nagasumi must guard Seto from those who would uncover her secret.