Seto's wedding

Manshio Nagasumi is an ordinary middle school student studying in a middle school in Saitama Prefecture. One summer vacation, he suddenly drowned while on vacation at the beach. When he was unconscious, he was rescued by the beautiful mermaid Miss Seto Chan. However, there is a rule in the mermaid world: if a human sees the true form of a mermaid, one of the two parties must choose to die. The last resort to avoid this iron law is to become a member of the mermaid family. Between death and forced marriage, Yongcheng was forced to make the decision to marry Chan. Thus, the love drama surrounding Yongcheng and Chan and various mermaid tribe members begins...