is a Japanese author.
Kogyoku was born in Kanazawa, Ishikawa Prefecture.
Due to enjoying the works published by , an imprint publishing works geared towards young girls, she began writing novels while still in elementary school. When she was attending Kanazawa Sakuragaoka High School, she was part of a literary club that took part in the where she won the . She then attended Kanazawa University and graduated from the department of literature.
In 2006, her novel Horned Owl and King of the Night was the Grand Prize winner in the thirteenth Dengeki Novel Prize held by ASCII Media Works (formerly MediaWorks).