Kidomaru is an oni (or ogre, a creature from Japanese folklore) that appears in Kamakura period texts such as the collection of stories entitled "Kokon Chomonshu" (A collection of Tales Heard, Past and Present).
鬼童丸、鬼同丸（きどうまる）は、鎌倉時代の説話集『古今著聞集』などに登場する鬼。