Kodaka made her debut in 1989 with Sessa Takuma! in Shounen Champion, but when she stopped writing shounen manga and started publishing Sessa Takuma! with Biblos, she transformed it into a BL story instead. Today she is one of the most popular Boys' Love authors.
Matoh Sanami taught her how to draw using a shoujo-style. Matoh Sanami and Kazuma Kodaka are actually very good friends.
Her brother, Ichijou Kazuya, is a seiyuu.
Since she got her start doing shounen manga, she was embarrassed to write under her real name, so she wrote under "Kazuma," which is a man's name, but she decided to keep it when she started writing female-oriented stories.
Her doujinshi circle is called K2 Company.