Kyoko Hori, the most popular girl in her class, dresses plainly at home and takes care of housework. One day, Izumi Miyamura, the class loner, discovers her secret when he escorts her younger brother, Sota, home from a nosebleed. Hori discovers that Miyamura wears piercings outside of school and has tattoos, but the two decide to keep each others' secrets and befriend each other as Miyamura continues to visit to play with Sota. Meanwhile, Toru Ishikawa, a classmate, befriends Miyamura in spite of his feelings for Hori and tells him that he plans on confessing to her. Miyamura puts distance between himself and Hori until she confronts him, upset that he had avoided her to protect her reputation. The two make up, with Hori explaining she rejected Ishikawa. As Miyamura recalls his dark past, for a class project, Hori, Ishikawa, and Yoshikawa form a group with him, and he realizes he has them to call his friends.

As summer arrives, Sakura falls in love with Ishikawa when he helps her pick up papers she scattered. Hori gives Miyamura ice cream, which he shares with Ishikawa and Sengoku. Hori and Miyamura lose a game among their friends and they are punished to buying drinks for them, with Ishikawa misunderstanding what happened between them. Ishikawa notices Hori is irritated when Miyamura's true appearance, revealed in a magazine article, draws attention from several girls. When Ishikawa confronts Miyamura about Hori, Miyamura denies that she has feelings for him, and they get into an altercation.

While out in town, Hori and Ishikawa meet Shindo, Miyamura's middle school classmate. Later, Hori falls ill, and Miyamura nurses her, learning more about the loneliness she experiences in the process. Believing Hori to be asleep, Miyamura confesses his feelings for her. However, Sota reports that he saw Miyamura with another girl, unaware that she is Shindo's girlfriend Chika. Hori becomes upset and avoids Miyamura, culminating in her throwing her textbook at him. When Miyamura arrives at her home to return the textbook, the two apologize to each other. Hori allows Miyamura to explain, and they are interrupted by her father, Kyosuke.