SHK (Real Name Shin Hyun Keun) is a music composer well-known for his work in various music games, like O2Jam, Sabin Sound Star, Ez2Ac, Pump it Up, Rhythm Square and Cytus. There has been some controversy regarding SHK's gender, mostly because of a song of his, "Reality", in which a woman's voice can be heard singing in Japanese. Said voice, however, does not belong to him but rather to a Korean singer called "Ruriling", who is a friend of SHK. Lately, he has been using a Vocaloid, SeeU, as the voice for many of his projects.