After that, Sōnen received an imperial appointment to Nanzenji. In his later years, he became abbot of Enpukuji 圓福寺 in Kyoto, and later as the former abbot supported the restoration of Enpukuji. He retired to the Tenjun’an 天潤庵 hermitage at Kenninji. He died at Enpukuji in 1345 at the age of 70. His posthumous title is Fusai Daishō Zenji 普濟大聖禪師. Sōnenʼs disciple Daiyō Shūnin 大用宗任 and other students took over the Tenjun’an 天潤庵 as a mortuary sub-temple (tacchū 塔頭) dedicated to Sōnen. Zentsūji also became a branch temple of Tenjun’an. There is a theory that Kao Sōnen and the noted ink wash painter Kaō Ninga 可翁仁賀 (d.u.) are the same person, but this has not been proven.