Kurumiko Daishikyōgawa, a middle school girl working as a beachside popsicle vendor, hides a past marked by tragedy. Orphaned when her parents perished in the sinking of the cruise ship *Premium Ambriel*, she harbors lingering guilt toward Souta Hatate, the accident’s sole survivor, convinced his suffering outweighs her own. This guilt colors her early interactions with him, though their shared grief gradually forges an empathetic bond.

Her role as a vendor triggers their first encounter, highlighted by a visible story flag designating her as a cleric within Souta’s party. When Akane Mahougasawa buys her entire stock, Kurumiko guides Souta to a secluded cave she visits during moments of sorrow. A collapse traps them inside, testing her resolve until Souta’s rescue and subsequent invitation to join Quest Dorm as his adoptive younger sister. This pivotal moment shifts her trajectory from solitary guilt to communal belonging.

Though occasionally prone to childish quirks, Kurumiko upholds a disciplined work ethic, shaped by her parents’ lessons on self-reliance. Prior to joining the dorm, she gravitates toward Souta not only for their shared orphanhood but also his simple act of purchasing her popsicles. Her growth lies in shedding isolationist tendencies, embracing interdependence through her sibling-like bond with Souta and the dorm’s collective support.

Her maroon twin pigtails, square bangs, and amber eyes mirror her name’s etymology: “Kurumi” (walnut) and “ko” (child), paired with a surname blending “daishikyō” (archbishop) and “kawa” (river), symbolizing her clerical role and thematic connection to spiritual guidance. Within the narrative, she propels story flags critical to Souta’s mission to defy fate, her arc charting a path from guilt-driven solitude to purpose within a chosen family.