Yuko Yoshida (吉田 優子 Yoshida Yūko) / Shamiko (シャミ子) is a 15 year old high school student of Sakuragaoka High School who, one day, wakes up with horns and a tail. She is then tasked to locate and defeat a magical girl, but it's not going as planned at all.
Despite her ancestry, Yuko is physically weak. Now that she's awakened her abilities as a demon, she is determined to break her family's 40,000 yen per month living curse.