Amidst all of the issues that any teenager girl usually has, Aika Tsunaboshi also secretly an Magical Girl. Much likes the ones you would typically see in anime and manga. Except these ones also hunts demons on the side. One day, while fighting against her nemesis, she is forced to make a decision and temporarily transfer her powers to someone in her family. Which according to her partner (AKA Sacred Beast) Nyamo, the Nekomata, was intended to go to her older brother, Akira Tsunaboshi. Who is always mistaken for a girl and barely able to form a full sentence towards strangers, which leaves him prone to many misunderstandings. However, during the transferring process, Aika got cold feet at the last second and her partner, alongside her magical powers were sent somewhere else. About to be stricken down by her assailant. Aika is saved by a strange fat man. Her savior... just happened to be one of her detested teachers, Shinjirou Tsunaboshi... and also her uncle, who happened to be passed out drunk in the gym storage nearby. His perpetual state of hangover, carefree nature, unrensponsible and perverted tendencies that earned him the title "Ero-Sensei" which caused many shenanigans and headaches for Aika to deal with most of her life. The utter shock of seeing her uncle wearing her uniform, a frilly dress, alongside a set of cat ears, tail and everything made her pass out on the spot. By the time she woke up, not only he was casually partying with both her partner and the demon. Shinji became best friends with them and convinced the two to form a strange alliance between himself, her demonic nemesis and through Nyamo, sent his unprecedented proposal to Arcadia, the faction behind managing and recruiting all Magical Girls. Would Arcadia even consider Shinji's suggestion and his abnormal circumstance? Will Aika be able to handle yet another stress placed on top of her social life? Will Aika's powers ever return to her? Even if it does, will she be able to manage to put up with her troublesome uncle for the sake of justice until then? Only one way to find out!