Kazui is a small boy with spiky orange hair and large dark orange eyes that closely resemble his mother's. He wears a light blue hoodie and white pants, rarely seen without his favorite hoodie even when transformed into a Shinigami. His face carries a constant grin, and he approaches even the strangest spiritual phenomena with innocent curiosity. Uninvited visits to Hiyori Sarugaki's home and cheerful interactions with remnants of Yhwach's Reiatsu are typical for him. He happily helps Souls depart after death, performing an eldritch ritual with ominous apparitions instead of traditional Konso, completely unbothered by the darkness around him. When a skeleton on the Gates of Hell stared at him, Kazui simply grinned back obliviously.