Shimizu Kosho was born in 1911 as the sixth son of the Higashimichi family and was named Mutsuji. After graduating from middle school, he trained under Shimizu Kimitoshi at the sub-temple Hougon-in of Todai-ji and later came to be known as Shimizu Kosho. He studied at Ryukoku University and then pursued Zen Buddhism at Tenryu-ji.
In 1963, Kosho became the head of the Todai-ji Kindergarten, where interaction with children inspired him to start creating unique small mud Buddhist statues known as "Dorobotoke" and to begin painting with ink. From 1971, he also maintained a diary of drawings for over 20 years.
In 1975, he became the head of the Kegon school and later the head priest of Todai-ji, successfully overseeing the major renovation of the Great Buddha Hall. Despite his busy schedule, he continued to enjoy pottery by visiting various kilns across the country.
Throughout his life, he continued to produce calligraphy and pottery artworks. These creations, along with his collected art pieces, were donated to Himeji City, leading to the opening of the Himeji City Shosha Art and Craft Museum in 1994, where his works are permanently displayed. Shimizu Kosho passed away in 1999 at the age of 88, but his works remain popular to this day.