Leo Kakinoki is a middle school student born in 1990. He possesses tan skin, light reddish-brown hair, light brown eyes, large lips, and wears rectangular glasses. His typical attire consists of a light yellow hoodie with light gray sleeves featuring an owl and "2001" decal, light blue-gray pants displaying cerulean blue patches on the front pockets, a dark periwinkle baseball cap matching his hoodie's design, and white sneakers. He is Hajime's best friend and shares a close friendship with Satsuki. Initially presenting a nerdy stereotype, Leo self-identifies as a specialist in ghosts and supernatural phenomena. He actively researches rumors and legends online, providing the initial background on encountered spirits for his group. Despite employing a logical approach to analyze supernatural events, he frequently reaches incorrect conclusions. He demonstrates proficiency with a camera, using it to document the paranormal activities the group experiences. Leo exhibits an arrogant streak and susceptibility to pride. This manifests when he becomes overly confident after leading a school Fine Arts festival project and when he obsessively attempts to prove the existence of the ghostly webpage Yomi-net to skeptical friends. He also displays cowardice in dangerous situations despite attempts to appear brave. He joins a team focused on studying monsters resembling Ohma in personality and traits, deepening his engagement with supernatural investigations. His primary narrative function involves supporting ghost-hunting efforts through research and documentation, though his findings often inadvertently complicate situations. In the English adaptation by ADV Films, his characterization includes specific cultural elements: he and his family are depicted as Jewish, incorporating additional dialogue traits not present in the original Japanese version.