Shuen studied the Hosso Sect teachings under Kenkei of Kofuku-ji Temple in Yamato Province, served as one of the overseeing monks during the service celebrating the completion of Konpon Chudo Hall on Mt. Hiei in the year 794, and was consecrated by Saicho in the year 805.
大和国興福寺の賢憬に法相を学び、794年（延暦13年）比叡山根本中堂の落慶供養の際その堂達をつとめ、805年（延暦24年）には最澄から灌頂を受けた。