Bō, a convict granted redemption, joins a covert operation as a replacement for a fallen Shinsengumi captain. He adopts the identity of Sanosuke Harada within this substitute unit. His recruitment hinged on a singular promise: unlimited food access in exchange for service, satisfying his prodigious appetite. Towering and physically imposing, he wields extraordinary strength, rendering conventional swords obsolete. This power enables him to wield a spear with devastating efficiency as his primary weapon. Unexpectedly, beyond combat, he displays refined proficiency in calligraphy—a stark contrast to his rugged exterior. After the Masked Demons devastate Kyoto, he engages actively in the city's reconstruction. This experience of meaningful contribution and earnest praise sparks a profound shift, solidifying his genuine satisfaction with joining the substitute Shinsengumi.