Ryōka Yamakawa, a 17-year-old second-year student in Class 5 at Seitetsu Gakuin High School, serves as the ranged combatant of the White Kämpfer faction, wielding a Gewehr modeled after an Ingram MAC-10 submachine gun. Her tactical reliance on distance engagements contrasts with Akane Mishima’s close-quarters aggression, positioning her as the White Kämpfer’s counterpart to Akane’s role among the Blue faction.

Timid and insecure compared to her assertive peers, Ryōka habitually preempts errors with overly formal apologies, a tendency that strains alliances. Though privately uneasy about ethical compromises, she pragmatically aligns with faction demands to retain Kaede Sakura’s approval, balancing personal discomfort with survival within the group’s hierarchy.

Recruited after the Red and Blue factions established a truce, Ryōka operates within the White Kämpfer’s emergence as a third power. Her aversion to confrontation manifests during clashes—she withdraws from intra-faction disputes, even as opponents capitalize on her passivity. In one engagement, she refrained from intervening as teammates quarreled mid-battle, inadvertently allowing rivals to seize advantage. This reluctance underscores her preference for evasion over direct conflict, diverging sharply from her faction’s combative ethos.