Artist, illustrator, colorist. 

Japanese name: 磨鞘 一佳 (the artist said "read this name either way, Masaya Ichika or Masaya Kazuyoshi")
The other name: 磨鞘 いちか (Masaya Ichika)
Circle & site name: 人生堕落研究所 (Jinsei Daraku Kenkyuu-jo, Life Degeneration Laboratory, aka. LDL)
The other circle name: U.N.Keepers (the other member: Usui_(UNK))
masaya ichika