Keigetsu Shu

Maiden of the Shu Clan.

She has a strong inferiority complex and is hated by everyone because of her despicable words and actions, earning her the nickname of "sewer rat".

Jealous of Reirin, who is the complete opposite of herself and loved by those around her, she uses her special forbidden magic to switch bodies with her on the night of the Double Seven Festival.

(Source: Official Website, translated)