Tokiya is a longtime friend of the protagonist Shirō, sharing a history with both Shirō and Akane as part of their central friend group. When Akane returns to Minami Shimabara from Tokyo during summer, Tokiya joins Shirō and Akane exploring the city. As they navigate waves of nostalgia and complex emotions during this outing, Tokiya is present when the mysterious creature Goron confronts them. This encounter initiates significant events affecting the city, and Tokiya participates alongside Shirō and Akane in these unfolding events.