有須 星子

Key Emotion: Jealousy
Rank: A-rank

Yuuji's energetic younger sister who is a carrier, carrying Little Mermaid's spirit inside her. Originally not a resident on this island, Seiko is soon sent to her older brother as the story progresses, and allows the awakening of her own “Princess Syndrome”. Seiko is an extreme brocon who is really attached to her brother, and also considered the moodmaker of the group. Her trigger emotion is "jealousy", which allows her to "erase" things, especially clothes.