Yuzo Kashima, a stout man in his forties standing 178 cm tall, possesses sharp blue eyes, dark olive-brown hair, and chin stubble. He typically wears simple clothing, often a gray t-shirt layered under a white, black, and red tracksuit.

Formerly a member of the original Spring Troupe at MANKAI Company, Kashima now works as an actor, theater director, and lecturer at a theater school. He maintains close historical ties to MANKAI, having shared friendships with Izumi Tachibana's father and Hakkaku Ikaruga during his troupe days; contact was lost after the company disbanded.

Driven by his attachment to MANKAI's legacy, Kashima voluntarily returns in his free time to coach its current members. His uncompromising, straightforward coaching style prioritizes honest, unsugarcoated critique over preserving feelings, earning him the moniker "Demon Coach" for his harsh, Spartan methods. He believes this rigorous training and actionable feedback are essential for actors to improve.

Despite his stern demeanor, his intentions are well-meaning and he holds genuine fondness for MANKAI Company. This ongoing involvement is exemplified when he contacts Izumi's father after a performance, acknowledging her progress while emphasizing areas needing growth, reinforcing his commitment to the troupe's development.