Hiroya Oku is a mangaka who is the creator of Gantz, Zero-One and HEN, all of which have been serialized in Young Jump. His manga often contain explicit violence and gore, as well as sexual situations. In an interview conducted with an anime magazine in 2005, Hiroya stated that he "adores girls with big breasts".

He won the second prize of the Youth Manga Awards in 1988, under the penname Yahiro Kuon.

He designed a character for Namco Bandai's Xbox 360 and Playstation 3 fighting game, Soulcalibur IV named Shura.

He was the assistant of YAMAMOTO Naoki.