He was selected as a Buddhist priest to study overseas at the age of 25, went to Tang Dynasty China and studied both Yuishiki doctrine (theory that all existence is subjective and nothing exists outside of the mind) and Hokke doctrine for 31 years there.
25歳で留学僧（るがくそう）となって唐に渡り31年間唐にとどまり、唯識・法華の両教学を学んだ。