This study examines Komagaku , one of the pieces of Japanese court music and dance, focusing its origin. Uniquely in , the dancer wears a costume with rat patterns. The examination of the relationship between the Korean Peninsula and focusing on the rat on the costume of , shows that the country showing the most records of rats as spiritual beings is Silla. Thus, in order to find any relationship between the Korean Peninsula and using the image of rat, it may be more efficient to examine Silla than Goguryeo or Baekje. In addition, uses Imha(臨河), Imga(林歌), or Imga(林哥) for its mark. Among them, Imha(臨河) has the same Chinese characters as ‘Imhasa(臨河寺)’ of Silla. Buddhism utilizes music and dance to serve Bul(佛), Beop(法), and Seung(僧) and promulgate Buddhist doctrines. Here, 『Taigenshou(体源抄)』 has records showing the relationship between and Buddhism. In addition, rats are not irrelevant to Buddhism, also appearing in 『Jataka(本生譚)』. If is closely related with Buddhism, then its relationship with Imhasa can be meaningful, as they use the same marks. Looking at the remains of Imhasa such as brick pagodas, its origin traces back to Silla Dynasty. Considering the relationship between and Imhasa, it is highly possible that originates from Silla among the three countries of the Korean Peninsula.