Rei Kiriyama is a 17-years-old shogi (Japanese chess) player. He debuted as a professional shogi player when he was in middle school. He lives by himself in Tokyo, because his parents and younger sister died in a traffic accident when he was little. One day, Rei meets three sisters who are his neighbors. The three sisters are Akari, Hinata and Momo Kawamoto. This is his first meeting with someone outside of the shogi world in many years. Having meals with the Kawamoto family brings warm feelings to Rei. As Rei continues his shogi career, his interactions with his neighbors allow him to grow as a shogi player and as a person.