The calligrapher Koshin Kawatsu was born Hiroyoshi Kawatsu on 31 July 1941 in Matsue, Japan.
In 1960 Kawatsu began to study calligraphy under Bokudou Kanamori. He graduated from the Faculty of Education of Shimane University (1964). In 1985 he joined the Shimane Calligraphy Association. In 1985 he travelled to Munich, Germany, to present works of calligraphy. In 1989 he founded the Shokou Bokujin-kai Calligraphy Association. He received the following distinctions: Bokujin-prize (1996, 1999). In 2001 he held a personal exhibition of calligraphy. In 2002 he became the Curator of the Matsue Public Library. He assumed the presidency of the following official bodies: Shinji Junior High School (1995); Matsue Daini Junior High School (1997); and The Hearn Society of Japan (2007).
Koshin Kawatsu lost his battle with cancer on 18 December 2009 in Matsue.