There was a parting song for MINAMOTO no Koremori, who became a retainer after yearning for koto played by Moronaga when he was exiled to Tosa Province at the young age of 19 in "Senzai Wakashu" (Collection of a Thousand Years), as well as the legend that he secretly travelled to Southern Song dynasty to learn music when he was young, but was restrained by the ghost of Emperor Murakami in Suma district and was taught the secrets of biwa instead.
『千載和歌集』には、19歳の若さで土佐に流される折に彼の筝を慕って家人になった源惟盛との別れの歌が載せられている他、若い頃に密かに南宋に渡って音楽を学ぼうと志して家を出た師長が須磨の地で村上天皇の霊に押し止められ、代わりに琵琶に秘伝を教えられたという伝説も残されている。