Alto meets Ichigo when he finds her lost choker. It is later revealed that Alto is actually Ryou Shirogane as a cat. It started when Ryou was a ten-year-old boy, living with his mother and father and a pet dog called Daisuke. Ryou's father, Dr. Shirogane, showed Ryou around the lab.
During then, Keiichiro Akasaka worked as Dr. Shirogane's assistant. He then saw that his son, Ryou, was smarter than him. After an explosion inside the lab, Ryou's mother told Keiichiro to take Ryou to safety. When they were safe, Ryou told him that they can continue the experiment because he memorized the notes.
A few years later, Ryou and Keiichiro were ready to do the experiment. To make sure it was safe, Ryou put a tube of cat DNA on his neck, pushed the button, and he became a cat instantly. Ryou only changes into a cat when he needs to quickly get to a destination or help Ichigo change out of her cat form and back into her human form. If he stays a cat for more than ten minutes, he can't regain his human form back.
Alto is light grey, small, and wears a green scarf (which could actually be a bandana or a napkin) around his neck. He has light blue eyes, just like Ryou. The tip of his tail is kinked, though it may be coincidental, cats with kinked tails are sometimes seen as a sign of good luck.
- Mew Mew Amiche Vincenti (Italian) - Art
- טוקיו מיו מיו/Tokyo Mew Mew (Hebrew) - Art
- Mew Mew Power (French) - Alex
- Tokyo Mew Mew (Season 2 Portugal) - Art
- โตเกียวเหมียวเหมียว/Tokyo Mew Mew (Thai) - Al
- Družina Mjau - Mjau/Mjau - Mjau Tokio (Serbian) - Art
- In Spanish, Portuguese and Italian, "alto" means high or tall. In Spanish, it can also mean "stop." Also, "alto" is a pitch in singing below soprano.