Gurio Umino, usually called by his family name "Umino", is a socially-awkward friend of Usagi Tsukino and her best friend Naru Osaka. He is very intelligent , but at some point, he could be arrogant and a bit of a "Mr. Know It All".
He was usually the one who kept the others up-to-date on information on Sailor V, the strange crimes and rumors in Tokyo, and on students such as Ami Mizuno and Makoto Kino.
Umino is a 14-year-old boy with a blondish-colored hair. He was always seen with his school uniform in the manga. Also, his most notable trait were his large glasses with swirls in the lenses.
Also, while the Senshi did imagine that Umino was handsome without his glasses at one point, author Naoko Takeuchi did confirm that he in fact was handsome without them.
Dark Kingdom Arc
In Act 1, Umino first appears when Naru is reprimanding Usagi for eating her lunch and asks how Usagi did on the English test. He shows that he got a 95% on the test, but notes that he really didn't study for the test, claiming it was like a game for him, causing Naru to become rather irritated. Later, at lunchtime, when Yumiko mentions the recent jewelry store robbery, Umino informs that Sailor V caught them, and further informs Usagi of who Sailor V is, and of other strange crimes that have happened recently. The girls though start to talk about jewelry, leaving Umino ignored.
In Act 2, Umino is talking to Naru and Yumiko when Usagi overhears the conversations about Ami Mizuno, the genius girl with a rumored IQ of 300. He remarks that her sucess is due to the lessons at the Crystal Seminar, where she attends for prep school, and also mentions that while the prep school is expensive, it is not a problem for her, since her mother is a doctor.
In Act 3, when Usagi and Ami are about to board the 5 p.m. Sendai Route Bus, Umino pops up out of nowhere and warns the two not to get on the bus as it is the same route the "Demon 6 p.m. Bus" is on, although Usagi dismisses it as a rumor. He personally believed that the disappearances were part of a new method of kidnapping.
In Act 4, when Usagi and Motoki comment about the Princess of D Kingdom and how pretty she must be, Umino appears with a rare photo of the Crown Princess, they are rather surprised by her appearance, with Usagi noting that she looks a lot like him. Also, later in the chapter, when they discover that Princess D is very pretty without her glasses, the three imagine that Umino must be handsome without his glasses as well, but try to ignore it and claim that it's not possible.
In Act 5, he informs Usagi, Naru, and Yumiko about the new transfer student with supposed super strength, and about the rumor that she was kicked out of her previous school for fighting, except his information turns out to be wrong when Usagi formally meets her.
In Act 7, Umino finds Usagi, Naru, and Makoto having a discussion on Sailor V and her recent decline in activity. He then goes to deleting Ami's information of Sailor V, and believes that the one everyone should be investigating Sailor Moon nowadays. He then goes to say that he will be the first to find her, with his rather obsessive desire shows that he has fallen under the dark power spread by the Rental Shop Dark videos.
In Act 9, Umino makes a very brief appearance when Princess Serenity's tear becomes the Silver Crystal and gives off a very bright radiance, and he sees it through his telescope, thinking it's a new supernova.
In his final appearance in the Dark Kingdom arc, in Act 11, he informs Naru, who is rather hurt that Usagi hasn't been around very much, that Usagi is infatuated with the new employee at the Game Center Crown.
Black Moon Arc
At the end of Act 14, he makes a brief cameo walking with Usagi and Naru after school.
His only major appearance in the Black Moon arc is in Act 18, where Naru used him to track down a video about channeling, featuring Ms. Calaveras, and goes on to describe what channeling is and how it works for them.
Umino makes an appearance in the Battle Exam side story "Ami's First Love". Upon realizing that Umino is a "study nerd" who enjoys doing research, Usagi asks him if he knows anyone by the pen-name of "Mercurius". He replies that Mercurius is his friend, and that he can get him to meet her.
Later that day, Umino leads Usagi, Rei, Makoto, and Minako to the cram school Mercurius attends and introduces him to them.
His family name is like that of the Inner Sailor Soldiers, and is supposed to mean "ocean field", or a pun-like meaning of "of the ocean". Gurio, however, is written in hiragana, and has no exact meaning, but it could come from guri guri meaning "turning" or "to turn", since he wears glasses with swirls in them.
- Umino bears a resemblance to Princess D and Mercurius.
- In Codename: Sailor V, Minako Aino was friends with a boy named Gurikazu Amano, who Umino bears a striking resemblance to. Umino probably was based off Amano.
- In the DiC and Cloverway dubs, Umino is named "Melvin" and has a stereotypical nerd voice.