Fastest way to mail to Canada?

I want to mail something (regular a4 documents) as fast as possible to Canada.

Should i just use Japan Post, or is there a private company that is faster?

I send things back to Canada by EMS all the time. Relatively low cost and never had a problem

thanks Davie

Can I ask how long it took to arrive and if you printed the Electronic Advance Data label or just used a handwritten label?

EMS to Canada is not available with Japan Post (and had not been for over a year):
https://www.post.japanpost.jp/int/information/overview_en.html

And, as a foot note, JP Post will advise that items may take a LONG time. I recently shopped a bunch of boxes across the Pacific (full air mail as surface or economy not available) and they sat in Japan for varing durations before being sent. With a normal delivery time of 3-6 days, most were delivered in around two weeks.
If you want to send something quickly, try a courier company like FedEx (personally I've had bad experience with DHL, but that is an alternative).

gUnder normal circumstances,h Japan Postfs EMS would be the fastest. But I doubt it is accepted right now.
You might consider Yamato Transportfs international courier service – for Canada, they accept documents.

One of my friends, who has been shipping small parcels to destination around the world switched from Japan Postfs EMS to Yamato in view of the delays due to COVID19. (Japan Post does not have any aircraft on their own, that is why they have to wait for cargo space availability on commercial flights, and that is why there is considerable delay. Yamato, DHL or Fedex would be better as they have their own flights.)

Whoops, I should have said: under normal circumstances, gJapan Postfs EMS would be ONE OF THE fastest.h Fedex and DHL are usually faster than EMS.

I just checked, and Yamato quotes 7 days for documents to Canada, so Fedex and DHL would be faster then.

As a thought, as you are just sending A4 documents, and presumably not a huge volume, standard airmail is still operating and would be a cost effective method (and registered is an option too), but would take a week.
note: https://www.post.japanpost.jp/int/information/overview_usa_en.html
Previously I have used the EMS service to send JR tickets around the globe as a cost-effective and quick method to send those to people, but it just isn't being offered currently.