"Kitaro's Birthday" reveals the origin story of the yokai boy Kitaro and his tiny eyeball father, Medama Oyaji. "Neko Musume versus Nezumi Otoko" is the first of Mizuki's stories to feature the popular recurring character Neko Musume, a little girl who transforms into a cat when she gets angry or hungry. Other stories in The Birth of Kitaro draw heavily from Japanese folklore, with Kitaro taking on legendary Japanese yokai like the Nopperabo and Makura Gaeshi, and fighting the monstrous recurring villain Gyuki.