The honor of being the first Japanese feature-length animation is typically given to the 1945 propaganda film Momotaro's Divine Sea Warriors, and by pretty much every definition of "feature-length" that's correct. However, it was preceded by a 1943 film, Momotaro's Sea Eagles, running to just 37 minutes (the shortest standard definition for "feature-length", offered by the Academy of Motion Picture Arts and Sciences, puts the cut-off at 40 minutes), but marketed as the main attraction when it was released. And this is what the word "feature" means. So I'm going to declare it: we have here in front of us the first Japanese animated feature. It's just not a feature-length feature.

Regardless, Momotaro's Sea Eagles is the movie about the very cute bunnies, and the funny monkeys, and the brave doggies, who have merry slapstick adventures as they go on a very important mission to bomb the filthy American imperialists at Pearl Harbor. So, you know, that's awkward. All the more so because Momotaro's Sea Eagles is actually pretty good, and I was sorely tempted to just give it a flat four stars, because I am a formalist sociopath. But, like, the attack was officially found to be a war crime and all, so I have decided to modestly temper my enthusiasm.

Because, no two ways about it, the movie is pro-war propaganda. The director, Seo Mitsuyo, was an avowed leftist, who had even run into legal trouble in the '30s for his association with a radical filmmaking collective (he would return to full-throated leftism after the war, effectively ending his career as an animator), and it's tempting to wonder if he was trying to thread a quiet anti-war message into the film as a result. Certainly, the fact that the film takes great pains to show that every single American escaped the attack with his life intact suggests the slightest dilution of the unabashedly triumphalist tone the movie otherwise adopts, but I don't think it would do to follow that line of reasoning very far. Sometimes, a movie is just pro-bombing, and that is all there is to it.

The film is based on the story of Momotaro ("Peach Boy"), which I gather to be an enormously famous and beloved folktale that just about every Japanese citizen would know in some capacity. Among its details: on his journey to the island of demons, Onigashima, Momotaro befriended a dog, a monkey, and a pheasant, who helped him in his quest. Momotaro's Sea Eagles takes that as its launching point: here it's an entire phalanx of dog pilots and monkey co-pilots, with pheasant engineers as support staff, all on an aircraft carrier run by rabbits. Momotaro shows up only to give the order to attack Onigashima, which just so happens to look exactly like O'ahu. The great majority of the film consists of the flight over and the attack itself, both of which are structured around precisely the kind of mild cartoon slapstick of an early '30s Hollywood cartoon: to say that it feels like a Disney Silly Symphony animated by Fleischer Studios is pretty much exactly the feeling it evokes. And one gets the impression that the filmmakers were thinking in similar terms themselves, given that Bluto, from the Fleischers' Popeye series, is brought in as the main American bad guy, a hapless drunken lout so busy falling over his feet that he can't even run away properly, let alone mount a counterattack. They've even used the original Bluto audio, it sounds like, or found a local voice actor who can match Gus Wickie's haughty, hostile mutterings so perfectly that it's uncanny.

Also uncanny: watching the wobbly line drawing style of the early '30s applied to battleships as they're comically ripped apart by torpedoes and bombs and monkeys. I cannot over-stress this: Momotaro's Sea Eagles is an extremely normal funny animal cartoon, that just so happens to be vociferously propagandising in favor of a war of aggression. There are some very fun and creative gags, such as the way the monkeys make a chain of themselves to descend to the plane yards and then make a ladder of themselves to climb back up; more often, we just get very simple comic beats, like a monkey who gets his tail stuck as he's jumping from a plane that's about to explode, so another monkey has to shoot him in the butt. It's cheerful nonsense, done in a very appealing black-and-white line drawing style, with big expressions on the characters' faces and bright, nonstop music driving it forward (other than Momotaro announcing the attack, the film has no dialogue). The discordance between the style and the content is striking, but as it goes on - and it goes on quite a long time, long enough that it starts to get a bit boring, even - it starts to feel like the normal cartoon mayhem, in an odd way. A great many cartoons are destructive, in the same victimless, fast-moving, timed-to-music way we see here; it's only the knowledge that this is commemorating a very specific real-world ambush that makes this feel so unfathomably, indescribably bizarre.

The film's surrealism I take to be an accident, but it is a genuinely artful, ambitious work. Unlike much of later Japanese animation, especially the budget-conscious Japanese animation that would dominate for decades to come, Momotaro's Sea Eagles is animated at a very high frame-rate, leading to some beautifully smooth movements, especially of faces. The featured dog - the only animal distinguished from the rest of his species, by means of a bit circular patch around his left eye - is particularly striking in how he turns, grimaces, smiles, laughs, struggles with his headband, gives side-eye. But all of the animals have fluid, expressive movement throughout - Momotaro himself is the only bad animation, mostly because he's been overdesigned, with detailed eyes and ludicrous full lips that look distinctly disgusting in motion.

Beyond the elegance of the character animation, Seo put real effort into making this a rich film with a good sense of dimensionality and space,ย  moving characters back and forth along the Z-axis in unnecssarily fussy ways, and panning across rows of animals standing at rapt attention by moving each row at a separate speed, to create a strong feeling of depth through parallax. As characters turn around, their furry bodies shift and sag and wobble in three directions, all spiraling together; they feel genuinely fleshy and malleable. It's showing off, pure and simple, applying the most sophisticated Disney-style manipulations of volume and space to simple, clean line drawings. Seo was an established animator by this point, and the feeling one gets is of somebody grateful to have the resources to indulge all the things he learned and figured out, creating some very lovely and needlessly busy animation apparently just for the pleasure of animation itself. There's the way that all the rabbits ears blow in the wind, all of them doing slightly different things, or the way that as crowd animation cycles, it's every third or fourth figure who repeats the cycle, rather than every second. Even the bravery to attempt animating someone as busily designed as Momotaro speaks to the underlying impetus: make this look as spectacular and splendid as possible, using detailed background drawings and grace notes of movement to push this far beyond the simple silly animal comedy implied by the design.

This doesn't last much past the start of the attack - the bombing itself is basically just very straightforward gags done in a by-the-books style - but it allows the movie to make an enormously striking impression as soon as it starts. The thing about the film: it's not just propaganda, it's good propaganda. It's appealing, fun to watch, and lavish enough that its very form serves as an argument that Japan can beat America at its own game (for what is more all-American than funny animal slapstick cartoons?). It's a fluffy children's comedy that also demonstrates top-tier mastery of the medium, and it's downright distressing how easily I found myself getting swept away by that mastery. It's simultaneously cute and atmospheric, and prone to depictions of uncomfortably engaging violence - an excellent proto-anime film, in other words, and while I am loath to say "you should go watch that impressive and fun movie about how it great it was to bomb Pearl Harbor", you shouldn't not do that. It's not like any of us are going to be convinced to support Imperial Japan at this late date, after all.