Yukihiko Kitahara is a Japanese composer. He originally worked for Data East and TAD Corporation. He is best known for his soundtracks for Cabal and Toki. It appears he left the game industry around 1989.
For his arcade music, he either used or had his music arranged into Michiya Hirasawa's sound driver, as confirmed by the text found in the game's audio engine. This was also verified by Akira Sakuma.
Staff photo from Toki (ARC)
In Toki (ARC), while there is a "Kitahara" listed in the game's credits, this is actually the designer Haruki Kitahara. Yukihiko is credited as TEN., as confirmed by Akira Sakuma in the Tweet linked above. Sakuma explains that it is short for Tennou (通称 = Alias or Nickname).