Mahiru Seki

As a former middle schooler and a longtime childhood friend, this character shares deep-rooted connections with both Kou Yamori and Akira Asai. Her history is defined by these enduring bonds, forming a central part of her social circle. Navigating life alongside her old companions, she brings a sense of familiarity and shared past experiences to the group's dynamic, making her a key figure in the lives of her lifelong friends.