Rei Kiriyama is a fictional character from the manga and anime series March Comes in Like a Lion. He is a 17-year-old professional shogi player who struggles with personal and emotional challenges. Rei is known for his introverted nature and often feels isolated, reflecting the complexities of his life and career. Throughout the series, Rei interacts with the 3 sisters of the Kawamoto family, who help him navigate his feelings and find a sense of belonging. His journey explores themes of loneliness, friendship, and the pursuit of happiness, making him a relatable character for many viewers.