What is "ryuko"

Ryuko may refer to one of the following:

• "Ryūkō" (song), a 2009 song by musician Ringo Sheena

is a song by Japanese musician Ringo Sheena, which acted as one of the promotional songs from her fourth album Sanmon Gossip in 2009. The song was produced by Sheena's former Tokyo Jihen bandmate Masayuki Hiizumi, and was a collaboration with Hiizumi's jazz ensemble Pe'z, as well as hip-hop group Maboroshi members Daisuke "Mummy-D" Sakama and Tomoyasu Takeuchi.