Masaki Kousuke (柾昊佑) is the guitarist, synthesizer, composer and arranger of the Japanese pop group moumoon.
- Birth Name: Masaki Kousuke
- Birth Date: June 22, 1977
- Birth Place: Ishikawa Prefecture, Japan
- Hobbies: Making curry, tennis, snowboarding, baseball, golf
- Favorite Artists: The Beatles, Carole King, Alanis Morissette, QUEEN
- Favorite Color: White
- moumoon (2006-)