When the Cloistered Emperor Enyu (who had become a monk) passed away in February 991, she retired as the Empress Dowager on September 16 (old lunar calendar) of the same year and took the title of Tosanjoin, after the name of her residence, Higashi Sanjo dono.
正暦2年（991年）2月、円融法皇が崩御したが、詮子は同年9月16日_(旧暦)に出家して、皇太后宮職を停めて院号宣下を受け、居宅の東三条邸に因んで東三条院を称した。