In 1943 the Japanese navy funded a feature-length animated film in which a peach-born boy leads a force of animals in an aerial assault on an island of horned Westerners. Momotarō no Umiwashi — Momotarō's Sea Eagles — restages the attack on Pearl Harbor with a folktale hero in command. Its 1945 sequel, Momotarō: Umi no Shinpei, is the first Japanese animated feature ever made, was released four months before the surrender, and was watched as a child by Osamu Tezuka, who said it made him want to make cartoons.
That is where a study of Momotarō has to start, because nothing else in Japanese folklore has been so thoroughly conscripted, and because it demonstrates exactly what a simple story becomes when a state finds it useful.
The version everyone learns
An old woman washing clothes at the river sees an enormous peach floating downstream. She takes it home; when she and her husband cut it open, a boy is inside. They raise him. When he is grown he announces that he is going to Onigashima, Demon Island, to deal with the oni who have been raiding the district, and his mother makes him kibi dango, millet dumplings, for the journey.
On the road he meets a dog, a monkey and a pheasant. Each asks what he is carrying, is given a dumpling, and joins him. On the island the pheasant attacks from the air, the monkey scales the wall, the dog bites, and the demons surrender. They come home with the treasure.
It is tight, memorable, and structurally almost perfect: a gift, three recruitments in ascending order, a coordinated assault using each recruit's specific ability, and a return. It is also, in this form, no older than the Edo period as a text and was substantially fixed by Meiji schoolbooks.
The older version is about sex
Early otogizōshi versions from the Muromachi period run differently. In a widespread variant the old couple eat the peach themselves, are rejuvenated by it, and conceive a child in the ordinary way — the kaishun, "returning spring", type. The boy is then born to young parents rather than found in fruit.
The birth-from-the-peach version, the kasei type, appears to be the later refinement, and it won because it is cleaner and because nineteenth-century educators preferred it. That the standard children's tale is a bowdlerisation of a story about an elderly couple regaining their youth and their sex lives is one of the better-documented facts in Japanese folklore studies, and it is almost never mentioned in the picture books.
Peaches themselves are not incidental. In Chinese tradition the peach confers longevity and repels evil, and Japanese myth had already used them for that purpose: the three peaches Izanagi throws at his pursuers at the boundary of the land of the dead are given a divine title and a job. A child born from one arrives pre-equipped.
Okayama's claim
Okayama prefecture has adopted him comprehensively — millet dumplings sold at the station, a Momotarō avenue, a statue, festivals, a manhole-cover programme — and the claim rests on a local legend that is genuinely older than the folktale.
The Kibitsu tradition tells of Ura, or Ura-no-Wani, a fearsome figure said to have come from Korea and settled in a fortress in Kibi province, defeated by the imperial prince Kibitsuhiko-no-mikoto. Kibitsu Shrine performs a divination rite in which the sound of a cauldron heated over a fire is read as an oracle, and the shrine's tradition connects the cauldron to Ura's buried head, which is said to have gone on groaning. The identification of Kibitsuhiko with Momotarō, and Ura with the demons, was made and promoted in the twentieth century.
Aichi, Kagawa and Nara also have claims, and Kagawa points at Megijima, an island in the Inland Sea with a cave system marketed as Onigashima. None of these is the folktale's origin; all of them are places where the folktale has been attached to older material, which is a normal and interesting thing for a story to do.
The dumplings, and the deal
The recruitment scenes are the part Japanese readers quote, and the phrasing is fixed: each animal asks what is at his waist, is told, asks for one, and is given half a dumpling in exchange for accompanying him. It has become a business idiom — kibi dango is used for the small incentive that buys cooperation, and the phrase appears in negotiation contexts with mild cynicism attached.
The three animals themselves have been read as the zodiac opposites of the demon direction. If the demon gate lies at the ox-tiger boundary in the north-east, then the south-west quadrant holds the monkey, the bird and the dog — precisely the three recruits, in order. The reading is neat, it is widely repeated in Japan, and it may well be a later rationalisation of a set of animals chosen because they are useful in a fight. It is worth knowing and worth hedging.
Rewritten in 1945, and again after
The wartime use was not incidental or accidental: Momotarō appeared in textbooks, posters, songs and films as the model of the loyal young man who leaves home to punish demons on distant islands, and the demons were drawn with horns and Western features. After the war the occupation authorities and Japanese educators alike pulled him back sharply, and a generation of postwar retellings emphasised negotiation, the demons' repentance, and the return of stolen goods rather than the taking of treasure.
Akira Kurosawa, Ryūnosuke Akutagawa and others wrote sceptical versions. Akutagawa's short story of 1924 — which predates the worst of it — presents Momotarō as an idle young man who invades a peaceful island for loot and leaves the surviving demons plotting revenge. It is the sharpest reading anyone has given the tale, and it was written by a Japanese author at the height of the story's official popularity.
He is now everywhere in advertising and mascot design, and the modern versions are self-aware to the point of parody: a long-running mobile-phone advertising campaign has run Momotarō, Urashima Tarō and Kintarō as housemates for years.
Was Momotarō ever a real person?
No, and the local identifications with historical or legendary figures run the other way — a folktale attaching itself to a place's existing prince rather than a prince generating the folktale. The tale type itself, a miraculously born boy who defeats monsters with animal companions, is widespread and old, with relatives across East Asia, and it belongs to the class of stories that circulate rather than the class that record. What is genuinely historical is the use of him: Meiji curriculum design, wartime propaganda and postwar revision are all documented events with dates, and they have shaped the version in circulation far more than any medieval source has.
Why does he cut the demons a deal in modern versions but not older ones?
Because the ending is the part that carries the moral, and the moral has been rewritten at least three times. Edo versions are frankly about the treasure — the household becomes rich, which is the point of a story told to people who were not. Meiji school versions make it about duty and loyalty to a community. Wartime versions make it about conquest. Postwar versions, still the dominant ones in Japanese picture books, have the demons apologise, return what they stole and promise reform, and some have Momotarō refuse the treasure entirely. The plot survives all four because its middle section — the journey and the recruitments — is doing the work that makes the story memorable, and the ending is negotiable. Compare Urashima Tarō, whose ending has never been fixable at all.