It is the Taisho Period in Japan. Tanjiro, a kindhearted boy who sells charcoal for a living, finds his family slaughtered by a demon. To make matters worse, his younger sister Nezuko, the sole survivor, has been transformed into a demon herself. Though devastated by this grim reality, Tanjiro resolves to become a "demon slayer" so that he can turn his sister back into a human, and kill the demon that massacred his family.
Rihito Sajo, an honor student with a perfect score on the entrance exam and Hikaru Kusakabe, in a band and popular among girls, would have never crossed paths. Until one day they started talking at the practice for their school’s upcoming chorus festival. After school, the two meet regularly, as Hikaru helps Rihito to improve his singing skills. While they listen to each other’s voice and harmonize, their hearts start to beat together.
After meeting one day, a shy boy who expresses himself through haiku and a bubbly but self-conscious girl share a brief, magical summer.
