Kazuki Tanaka is a high school loner with a bad reputation, known as the "dumbest" student and constantly bullied. However, beneath his indifferent facade, he's smart, observant, and kind to those outside school. After a painful rejection in middle school, Kazuki trusts no one. His quiet life starts to change when a group of unique girls—shy, bold, social, tsundere, and yandere—crosses his path. Though uninterested at first, they gradually discover his true nature, leading to unexpected relationships that shake up Kazuki's daily routine.