But after four years, his teacher monk Kangaku Shonin said to Seishimaru 'I have nothing to teach you any more. How about going to study at Mt. Hiei?', so he went to Mt. Hiei in 1145, when he was only 13 years old.
しかし、4年の歳月が過ぎ師僧の観覚上人から「お前に教える事はもう何もない、比叡山に行ってはどうか」と言われ、勢至丸は比叡山へわずか13歳（1145年）で行く事となる。