Saicho went to Tang and learned mainly Tendai Doctrinal Studies, but it was popular to learn nenbutsu (Buddhist invocation), Zen, Buddhist precepts, and Esoteric Buddhism in China back then.
最澄は唐へ渡り天台教学を中心に学んだが、当時の中国では念仏や禅、また戒律、そして密教が流行していた。