Sun Seto

As the daughter of the powerful Yakuza leader Seto Gozaburo, this mermaid princess deeply embodies the chivalrous traditions of her people. Though she is a striking, model-like figure at school, she remains a devoted wife to Nagasumi. Because she has not yet reached adulthood, her transformation is unstable; any contact with water causes her legs to revert into a mermaid tail, adding a layer of constant tension to her daily life.