Rokumon is a black cat spirit who serves as the contract familiar to Rinne Rokudo, the main character in the anime series Kyoukai no Rinne. As a Nekomata, Rokumon possesses the ability to transform into a human-like form, although he typically appears as a small, adorable black cat wearing a bib featuring a skull emblem. Despite his cute appearance, Rokumon is a loyal and hardworking assistant, often helping Rinne with his duties as a Shinigami. His role in the series is to support Rinne, both in his spirit-related tasks and in his personal life.