カードファイト!! ヴァンガード
Doctor O is a dedicated and knowledgeable man in the Vanguard community. Always wearing white and a graduation cap, Doctor O provides insightful color commentary for tournament matches next to MC Mya while having a habit of forming the letter "O" with his hands. He likes to emphasize the long "O" sounds of his sentences (e.g. "D-"o"-kidoki desu ne!", which means "It's s-"o" exciting!"). The character is based on , a Japanese producer and businessman closely involved with the Cardfight!! Vanguard franchise and he is also known by the nickname "Doctor O".