Kosuke Oki (大木貢祐; Oki Kosuke) was born on April 28, 1986 in Kagoshima Prefecture in Japan, and is a singer-songwriter associated wint Lantis.

Oki debuted in 2016 with the opening theme song for the anime series バトルスピリッツ ダブルドライブ (Battle Spirits: Double Drive) with the song FRONTIER DIVE, off the single of the same name; the single would also include another theme song for the show – “FRIEND WIND”. One year later, he would release “EXTREME SPIRITS!” which was the main theme song for the バトルスピリッツ (Battle Spirits) trading card game and anime franchise he had provided a theme song for previously.

Other than producing songs for himself, he has also written songs for a myriad of other artists, which include 田所あずさ (Azusa Tadokoro).