Biography
This is not an artist. Please update your tags. The assorted theme songs are composed by a slew of J-pop bands. Most notable is DoCo, a play on the original band CoCo. They're usually drawn as the main girl characters of Ranma: Shampoo, Akane, Girl Ranma, and sometimes the other Tendou sisters.
https://ranma.fandom.com/wiki/List_of_musical_albums
Biography text from Last.fm, available under CC BY-SA.