The protagonist of the series. A five dan, Rei became a professional shougi player while in middle school. His parents and sister died in a traffic accident, and after that he was taken care of by his father's friend Kouda and became his apprentice in shougi. After becoming a professional shougi player and after completing middle school, he became independent of him and decided not to attend high school. After feeling a "need" to attend school however, Rei later joined a high school after a one-year delay. He lives in the city of Rokugatsu-chou (June town).