There is more than one artist under this name: 1. NM is a Russian rap project. 2. NM (originally named Nocturnal Mayhem) was a black metal band from Russia. 3. NM is a pseudonym of Japanese producer NAOKI.
Toshiyuki Kakuta (角田利之) is a composer best known for his work on Konami games. Kakuta is best known amongst fans of the Bemani series of games under his pseudonym of L.E.D. (and many combinations thereof; see List of Bemani musicians). He is also known for his composition work on the Zone of the Enders soundtrack.
OKUYATOS is one of the many aliases of Sota Fujimori. He specializes in aggressive electronica but occasionally will do an orchestral song or two for a game. He is most widely known as a Konami original artist making several songs for the Dance Dance Revolution series, and also the beatmaniaIIDX series, where he mostly produces trance music and house music.
Stone Bros. is one of the many aliases of NAOKI used for the hip-hop song Let the beat hit em! and its remix, featured respectively on the games Dance Dance Revolution 4thMIX and DDRMAX Dance Dance Revolution 6thMIX.