Doktor Zero is the chief medical officer of the starship *Arcadia*. His appearance follows a standard Leiji Matsumoto design: a pot belly and constant white medical attire featuring red outlines and a prominent red cross on the chest, completed by a matching white cap. Beneath this cap, he sports a balding head with gray hair at the back.

He provides frequent comic relief, often clashing dramatically with the ship's cook, Miss Masu, over his raids on her kitchen to procure sake. Despite his heavy drinking, Doktor Zero possesses exceptional medical skills that surface in critical moments; he performs complex, nearly miraculous surgeries on severe injuries when seriously needed.

His constant companion is his pet cat, Mi-kun (sometimes called Miaou). He adopted the kitten after its mother, gravely injured and apparently dying, brought it to his office. Mi-kun later joined him aboard the *Arcadia*. This distinctive cat appears in multiple Leiji Matsumoto works, including *Space Battleship Yamato* and *Galaxy Express 999*, and is based on the creator's own pet.