|Lives:||Azabu-Juuban, Minato-ku, Tokyo|
|Occupation:||Junior high school student|
|Associates:||Naru Osaka, Usagi Tsukino|
|Aliases:||Tuxedo Umino Mask, Doctor Guriguri|
|First Anime Appearance:||Crybaby Usagi's Magnificent Transformation|
|First Manga Appearance:||Act 1 Usagi - Sailor Moon|
|First PGSM Appearance:||N/A|
|English Name:||Melvin Butlers (dub, Mixx manga), Gurio Umino (Kodansha manga)|
|Actors:||Keiichi Nanba (anime), Roland Parliament (dub), Ben Diskin (Viz dub)|
Gurio Umino was the well-meaning but socially awkward otaku classmate of Usagi Tsukino and Naru Osaka. His usual function was to provide the girls with vital information, such as the existence of Sailor V and the identity of Mercurius in Ami's First Love, or to provide direction that led Usagi to a location targeted by the enemy. He later became romantically involved with Naru, despite initially having an infatuation with Usagi.
- Naoko Takeuchi has said in an interview that Umino was supposed to be handsome without his glasses.