In 838 or 842 he went to Tang China where he received instruction on esoteric Buddhism from Yizhen at Qinglong-si in Chang'an. During the Huichang abolition of Buddhism (c.845) he made pilgrimages to Mt. Wutai and Mt. Tiantai, collecting texts and images. In 847 he returned to Japan with more than two-hundred fascicles of texts.