Kai Shimada holds the rank of corporal within the Shinsengumi's second division. Physically strong, he performs diverse support duties for the unit, akin to his comrade Susumu Yamazaki. Appearing infrequently across official media, Shimada presents a generally friendly demeanor and maintains steadfast loyalty to his superiors and the Shinsengumi command structure. He features in multiple franchise installments. In *Hakuoki: Demon of the Fleeting Blossom*, he operates as a non-playable character providing assistance. His role evolves in *Hakuoki: Stories of the Shinsengumi*, where he emerges as a potential romantic interest for protagonist Chizuru Yukimura. Subsequent titles like *Hakuoki: Kyoto Winds* and *Hakuoki: Edo Blossoms* return him to a supportive non-playable character capacity. Shimada also appears in the film *Hakuoki: Demon of the Fleeting Blossom: Warrior Spirit of the Blue Sky*.