The film focuses largely on creatures from Japanese mythology known as yōkai (妖怪, variously translated as "apparition", "goblin", "ghoul", "spirit", or "monster"), which came to prominence during the Edo period[2] with the works of Toriyama Sekien.

[a] All three are retellings of the famous Japanese tale of Momotarō, which features the title character driving a group of demons away from Kikaigashima with the help of native animals.

At a local festival, he is chosen to be that year's Kirin Rider, referring to the legendary Chinese chimera, the Qilin:[b] a protector of all things good.

Katō - a demon whose mystical powers are born of his rage at the annihilation of Japan's local tribes - desires vengeance against the modern Japanese for their actions against the yōkai.

Katō feeds yokai into Yomotsumono's flames, fusing them with the numerous discarded tools and items to form kikai.

One such yokai, a sunekosuri[c] escapes and befriends Tadashi who attempts to obtain the Daitenguken[d] from the mountain as a right of passage for the role of Kirin Rider.

When Tadashi comes to his senses, he finds himself among yōkai as they discuss how to fix the sword; they ultimately decide to request the aid of the blacksmith Ippondatara.

However, due to Sata's actions, one of Azukiarai's adzuki beans ends up in the mix with Katō, causing a chain reaction of positive emotion that destroys Yomotsumono.

After the yokai take their leave, Tadashi and Sata find themselves on the street and the boy tells his first white lie to the reporter about Kawahime's feelings towards him.