1 Holy crap!  Where'd you find a subtitled version???  The one I have is a lousy-quality, unsubtitled copy (not that you need to know Japanese to get the gist).

The Nell was, indeed, just as much of a tinderbox as the Betty.  And the Japanese did have parachute units in WW2, as part of the Navy's "Special Naval Landing Force".  They were used in the Dutch East Indies; the Battle of Timor saw the largest grouping of them, nearly 700... and they did indeed face the Aussies.

About the only good account of the SNLF Paratroopers out there is the wonderfully titled Blossoming Silk Against The Rising Sun.  It's not particularly well-written, and needs an editor something fierce, but it's THE book on paratrooper assaults (both sides!) during the Pacific War.

2 Apparently there were some paratroops. And the army unit dropped on Luzon in 1944.

3

 The Nell had been shown to be a tinder box waiting for a match as early as the outbreak of fighting in China in 1937.  The IJN's initial contribution was via airstrikes by the two air groups equipped with the Nell - which soon had to come to a halt due to extraordinarily high loss rates.

Oddly enough, despite a patent lack on interest on the part of the IJN high command for expanding the SNLF, they were willing to introduce vertical envelopment, about the same time the USMC was experimenting with their own parachute force.

IIRC, the IJA paratroopers who landed in Leyte were destroyed by a force that including paratroopers from the 11th Airborne Division.

Then there was what US intelligence dubbed 'Operation Damocles', which was the plan to one-way a force of airborne raiders against the B-29 bases in the Marianas.  That was one of the primary reasons for Halsey and Task Force 38 raiding Hokkaido and northern Honshu in mid-1945.

4

This version was hardsubbed.

But the video quality is dreadful nonetheless. Not really surprising; we're lucky it survived at all.

5 So the enemy in this film are Dutch? That had never occurred to me.

6 I'm pretty sure they're supposed to be Australian.  At 1:08:45 on my copy, there's a quick skirmish between Our Divine Sea Warriors and three armored cars.  During the Battle of Timor, there was a similar action against Aussie armored cars trying to reinforce an aerodrome... which we also see, briefly.

The White Imperialism flashback just before the attack makes it seem more like Brits, but that could just be generalizing.

7 Come to think of it, the machine guns in the last shot are Maxim guns, aren't they?

8

Come to think of it, the machine guns in the last shot are Maxim guns, aren't they?

They are Vickers machine-guns, which were based on the Maxim guns (And made by the same folks, since Vickers bought out Maxim.).  It was the standard infantry heavy/medium machine guns of British and Commonwealth troops for a long time, including World War 2.  It was especially popular with the AIF, whose units tended to grab as many of the Vickers MG they could reach.

 

9

I'm pretty sure they really are supposed to be British, or at least wearing British uniforms. This film came out after the Battle of Singapore, and the mass surrender of over 80,000 British troops (as well as Indian and Australian, but all fighting under the British crown and wearing British uniforms with only differences in insignia to distinguish them) was a huge cultural disconnect for the Japanese, who couldn't believe soldiers wouldn't fight to an honorable death. Naturally, this gets exaggerated and flanderized by the propaganda machine of Imperial Japan.

10 The US Army still used those Brodie helmets until some time in 1942.

The major battles where the Japanese beat the living snot out of English speakers (American and British Empire) on land would have been the Battle of Singapore and the fall of the Philippines. I suspect, but cannot prove, that the Americans stationed in the Philippines were using the M1917 Brodie helmet.  If you are trying to raise flagging civilian morale, you'd want to people to remember those battles even though they occurred long before April 1945..

11

This kind of animated feature has a long lead time, and it's entirely possible the production took a couple of years (especially in war time when resources like film and celluloid were hard to acquire). The story boards may well have been done in early 1943 when things were still looking pretty good. (Especially from the point of view of the home front, because the government had been concealing its setbacks.)