Tonari no Kaibutsu-kun follows the uneasy bond that forms when Shizuku Mizutani, a girl who values little beyond her grades, crosses paths with Haru Yoshida, the violent troublemaker from next door. After a fight early in the school year, Haru has stopped attending class, and his blunt, unpredictable behavior makes him seem as intimidating as his reputation suggests. Yet Shizuku soon learns that he is also socially lost, has no real friends, and understands little about human nature.
When Haru suddenly decides that Shizuku will be his friend—and confesses his feelings the moment they meet—she is forced to deal with emotions and relationships she has little experience handling. Because Shizuku has spent so much of her life keeping others at a distance, even simple acts of friendship can feel confusing, and Haru's honesty pushes her to rethink the way she sees other people. As their connection deepens, she begins to notice a gentler side to him beneath the violence, while also realizing that the feelings growing inside her are more complicated than simple curiosity. Tonari no Kaibutsu-kun is a romantic comedy about two lonely students learning how to trust, connect, and understand one another.