Hiroko Oukubo

As the manager of the prefab team, she consistently operates one year ahead of her colleague Kō. Despite some teasing about her build, she possesses a genuinely kind and diligent nature. Sharing a background as a former foreign exchange student with Risa Shido, she exhibits a humble and grounded personality, contrasting sharply with the arrogance of some peers. Furthermore, she carries the lineage of the Seishu board chairman, though she remains unfazed by this status.