黒魔

Masaki Sekikawa (関川聖城), also known as Chroma (黒魔), is a Japanese music producer and SOUND VOLTEX contest winner mainly known for his articulate chiptune tracks, and often incorporates other sounds and even real instruments into his songs, unlike many other producers. Aside from chiptune, he also composes artcore and piano-based tracks.

Sekikawa often appeared in compilations from the salvation by faith records doujin label, to then generally contributing to SOUND VOLTEX-oriented circles. He also spends his time developing his own games.