He was the last of kentoshi to study in China but, since he was shoyakuso (a monk who stayed in Tang for a short period), he was not given a travel permit to Mt. Tiantai (perhaps because it was considered impossible due to his limited schedule) and he had no choice but to go back to Japan.
最後の遣唐使として唐に留学するが、もともと請益僧（短期の入唐僧）であったため目指す天台山へは旅行許可が下りず（短期の入唐僧の為日程的に無理と判断されたか）、空しく帰国せねばならない事態に陥った。