‘Yuharan’, known as the saint of the psychology department at XX University. And her hidden fan (or rather, stalker) ‘Imina’. One day, Mina is caught loitering suspiciously in front of Haran's locker by Haran and her friends. Accused of being a stalker and receiving suspicious glares, Mina finds herself in a dire situation without any proper excuse to defend herself. Just then, a beautiful girl, whom she has never seen before, appears and calls Mina ‘senpai’. With the help of this unknown ‘kouhai’, who approaches her with a friendly and gentle demeanor, Mina escapes the crisis. “Who are you?” asks the bewildered Mina, to which the beautiful girl introduces herself as ‘Jeseonwoo’, responding with a dazzling smile and a bright expression.