The story begins with Souma, the protagonist, breaking up with his childhood friend and girlfriend, Hanabi Kisaragi. Hanabi, a beautiful but verbally abusive girl, is shocked by Souma's decision, having always treated him as a punching bag for her insecurities. Souma, who has endured years of emotional abuse, finally finds the courage to leave her after a hospital stay due to stress-induced stomach ulcers. He realizes Hanabi's constant belittling has severely damaged his self-worth, making him feel worthless and dependent on her.
After the breakup, Souma blocks Hanabi on all platforms and experiences a profound sense of liberation, feeling physically and mentally lighter. The next day, he decides to reclaim parts of his life that Hanabi had controlled. He cuts his long bangs, which he had grown to hide his face on Hanabi's command years ago, and feels a significant shift in his perception of the world. Upon returning to school, Souma's new hairstyle causes a stir among his classmates, who are surprised by his newfound handsomeness. This sudden attention, a stark contrast to his previous invisibility, reaches Hanabi.
Souma's newfound freedom allows him to interact with his classmates more openly. He strikes up a conversation with Fumiko Yukishiro, a quiet girl who sits next to him. Their interaction is pleasant and natural, unlike his past experiences with Hanabi, where conversations were often one-sided and accusatory. Fumiko reveals she had noticed Souma's kindness in the past, such as tending to plants, and had wanted to talk to him.
Later, Souma encounters Hanabi, who attempts to reassert her control by blocking his path and demanding an apology. Souma firmly reiterates their separation, stating he no longer needs her in his life. Hanabi, enraged and humiliated, declares she will break up with him, a sentiment Souma welcomes.
In the following days, Souma enjoys his newfound peace, though he occasionally encounters Hanabi and her new boyfriend, Taichi Kirigaya, a popular athlete. Hanabi's attempts to provoke Souma by flaunting her new relationship are met with indifference.
The narrative then shifts to the upcoming sports festival. Souma's exceptional running speed, previously suppressed due to Hanabi's manipulation, is revealed during a relay race practice. This talent attracts the attention of his classmates and his teacher, who recognizes his potential to break regional records. Souma's classmate, Chiaki Harenchi, a member of the track team, approaches Souma. Harenchi is seeking revenge against Kirigaya, who stole his girlfriend and then abandoned her for Hanabi. Harenchi proposes a deal: he will coach Souma to win the relay race, and in return, Souma will help him defeat Kirigaya. Souma agrees, with the condition that Harenchi also coaches Fumiko, who struggles with running.
The three begin training together, forming an unlikely friendship. Souma finds enjoyment in this new camaraderie, a stark contrast to his isolated past. He observes Hanabi's continued attempts to get his attention, but remains focused on his new life and friendships. The chapters conclude with the eve of the sports festival, with Souma, Fumiko, and Harenchi having bonded through their shared goal.
