Born 12 September 1962. Family name Nangaku, given name Katsushi; Buddhist name Koun.

He was born the eldest son of Choonji, a temple of the Koyasan Shingon school at Kariya in Awaji City (formerly Higashiura) on Awaji Island, Hyogo Prefecture. He was around the brush from the age of two and began studying calligraphy in earnest on entering primary school. In middle school, working from the "Shodo Koza" volumes his father gave him (Nigensha), he became absorbed in the calligraphy of Hosui Matsumoto and Yasushi Nishikawa.

After graduating from university he studied under Joteki Ume, one of Japan's leading calligraphers and seal carvers. Alongside his activity in the calligraphy establishment he was also painting abstracts. That work caught the eye of Makoto Shimada of Kaibundo Gallery in Kobe (now Gallery Shimada), who mounted a solo exhibition of it — a turning point.

At Kaibundo he encountered the artists of the Gutai group and was struck by them. He also came across, by chance on a shelf at his old university, the "α section" printed in the journal "Bokubi", and took a flash of inspiration from it. The names listed there were formidable: Saburo Hasegawa, Jiro Yoshihara, Yuichi Inoue and the editor Shiryu Morita.

Through his thirties he belonged to the calligraphy establishment and worked mainly in seal carving. He has since left the central calligraphy world and now pursues new possibilities for calligraphy within the context of contemporary art.