Ryou is a genius. In episode 36, his father mentions that his IQ was over 180 at age of 10. He is headstrong, stubborn, rude, sarcastic, and occasionally reclusive. He teases Ichigo Momomiya a lot, but he has saved her on many occasions when she has transformed into her cat form. Also, he encourages Retasu Midorikawa to be more confident.
Ryou has tan skin and blond hair. He is tall and has aqua blue eyes, and is 15-years-old. When he's Alto, his eyes remain the same color. Ryou's Mew mark is on the side of his neck, which is always covered with the collars of his clothes.
Tokyo Mew Mew
When Ryou was 10, a Chimera Anima attacked his parents's mansion and killed them when he was out with Keiichiro. He tried to fight the Chimera Anima but Keiichiro held him back. He moved to America with Keiichiro and spent the rest of his childhood there, but then returned to Tokyo to perfect his father's work.
Tokyo Mew Mew a la Mode
After her first day of school, Berry Shirayuki almost falls down a set of stairs, but was saved by Ryou, who caught her. He then invites her to the Café Mew Mew and she accepts, then goes there to admire the treats that were being displayed.
Later, Ryou catches Berry by surprise and she falls into a pastry display. She runs away, and goes through a DNA infusion machine, which merges her DNA with that of two endangered animals: The Amami Black Rabbit and the Andes Mountain Cat. She passes out and when she wakes up, Ryou gives her a robot named R2003, which she nicknames Ucha.
The Mew Project
Ryou is dedicated to the Mew Project. When Dr. Shirogane's (Ryou's father) project was ready, Ryou was unsure that it would be safe, so he tested it on himself. He didn't have the right genes, so he didn't turn into a proper Mew Mew, but does have the ability to change into a cat for ten minutes. If he stays a cat for longer than that, he is permanently stuck in cat form.
When he is a gray cat, he goes by the name Alto. He wears a green scarf around his neck. Alto was introduced in episode 28. Alto saved Ichigo's life many times and has kissed her in order to return her back into human form. Ryou is the one who gave the girls their Mew Pendants so that they could transform. He was also the one who (with Keiichiro) chose which people would get the Red Data Animal DNA implanted in them.
- Ichigo Momomiya: Ryou seems to have a crush on Ichigo, and has kissed her many times to change her back from a cat into a human, though he is rude and demanding to Ichigo. He often likes to tease her.
- Retasu Midorikawa: Retasu used Mew Aqua to transform herself into a half-porpoise and kissed Ryou, but her feelings were one-sided so they decided to be just friends.
Name Changes (Manga)
Ryou keeps his name in all English manga translations. However, his first name is spelled slightly different in each one.
|Japanese||Tokyo Mew Mew||Kodansha||Ryou Shirogane|
|English||Tokyo Mew Mew||TokyoPop & Kodansha||Ryou Shirogane (TokyoPop)|
Ryô Shirogane (Kodansha)
|English (Singapore)||Tokyo Mew Mew||Chuang Yi||Ryo Shirogane|
Name Changes (Anime)
While most dubs either choose to use Ryou's Japanese name or 4Kids English name, some dubs have come up with their own, unique names for him.
|Language||Title||Name||Voice Actor / Actress|
|Japanese||Tokyo Mew Mew||Ryou Shirogane||Kouichi Toochika|
Junko Minagawa (Age 10, Ep. 36)
|English||Mew Mew Power||Elliot Grant||Sean Schemmel|
|Mandarin||Dōng Jīng Māo Māo
(Tokyo Cats / Tokyo Mew Mew)
|Léng BáiJīn||Liú Jié|
|Cantonese (TVB Dub)||Dung Ging Miu Miu
(Tokyo Mew Mew)
|Ling BaakGam||Ng Bok-Man (Raymond Ng)|
|Cantonese (ATV Dub)||Maau Maau Jin Deui (Cat Team / Mew Mew Team)||Ling BaakGam||Ho Wai-Sing (Alex Ho)|
|Italian||Mew Mew Amiche Vincenti
(Mew Mew Winning Friends)
|Ryan Shirogane||Davide Garbolino|
|Korean||Berry Berry Mew Mew||Jae-hee Gang||Il Kim|
|Hebrew||Tokyo Mew Mew||Rayou Shirogane||Daniel Zilberstein (Season 1)|
Dor Sarugo (Season 2)
|Brazilian Portuguese||As Super Gatinhas
(The Super Kittens)
|Elliot Grant||Thiago Longo|
|Portuguese (Season 1)||Mew Mew Power||Elliot Grant||Mário Centelo|
|Portuguese (Season 2)||Tokyo Mew Mew||Ryan Shirogane||Quimbé|
|Danish||Mew Mew Power||Ryou Shirogane||Simon Stenspil|
|Thai||Tokyo Mew Mew||Ryou Shirogane||N/A|
|Albanian (Albania Production)||Vajzat Mjau - Mbrojtëset e Planetit
(Mew Girls - Defenders of the Planet)
|Eliot Grant||Roland Saro|
|Albanian ("Jess" Discographic)||Luftëtaret Mace
|Ryan Shirogame||Jorke Broka|
|Elliot Grant||Károly Moser|
|Latino Spanish||Miau Miau Power
(Mew Mew Power)
|Elliot Grant||Wolfang Galindo|
|French||Mew Mew Power||Elliot Grant||Christophe Hespel|
|Dutch||Mew Mew Power||Elliot Grant||N/A|
|Serbian||Družina Mjau - Mjau / Miau - Mjau Tokio
(Mew Mew Team / Tokyo Mew Mew Team)
|Elliot Grant||Nebojša Milovanović|
|Croatian||Mijau Mijau Družina
(Mew Mew Team)
|Bulgarian||Силата Миу Миу / Silata Mew Mew
(Mew Mew Power)
|Greek||Mew Mew Power||Elliot Grant||Stamatis Gardelis|
|Turkish||Mew Mew Power / Sihirli Kızlar
- The different meanings for Ryou's first and last names have a lot to do with wealth. "Ryou" can mean "angle", "edge", "corner", "power", "majesty", "dragon" and "spirit", and his last name, "Shiro" can mean "white", "gane", (money, or gold) and "platinum".