As an "entrepreneur" (closer to a freelancer/independent contractor, self employed through a company I created) that's currently living in Japan, a few notes:

- Things get a lot easier when a Japanese person is involved.

- Paperwork pain will be real, hire someone else to do it. Japan is almost completely about the appearance of propriety -- getting everything filled out properly is 90% of the difficulty.

- Hire a cheap japanese accountant, at least for the first year. Once you have your feet under you, then look into how to use the efiling system (most accountants just do this for you anyway, japan has an absurd amount of their taxes filed electronically, despite their paper-heavy seeming nature). (https://asia.nikkei.com/Politics-Economy/Policy-Politics/Jap...)

- Initial capital requirements are a thing, you can actually get away with a fairly small amount though, like 10/20k USD -- this is impossible in countries like the US where you need millions to even get in the H1-B LOTTERY (so even if you get in, you still maybe don't win). Japan is surprisingly lax, and I think they've been this way -- it's not even a recent change.

- You will never be completely trusted as a foreigner in Japan, nor will you ever completely fit in.

- Japan is VERY easy to live in, even for someone who doesn't speak Japanese. While this is true, you should strive to speak japanese if you live in Japan -- your experience will be severely limited otherwise.

- There's a monthly HN meeting here that's not half bad (https://hntokyo.doorkeeper.jp/events/upcoming)

- Japan's tech skill is low. While I expect people on HN to know a little more, the mainstream media often only catches a whiff of japan at the peak of it's technical prowess (robots in Kyoto, interesting breakthroughs, etc), but the vast majority of businesses here are WOEFULLY inefficient and have not embraced technology and the current rush to build good technical knowledge. Sending a fax for business purpose (like for example your startup sending a fax to another company to get them to perform some function) is a thing that people actually expect you to do here, while offering no API alternative or anything.

- The japanese market is NOT your home market, and not even some generic "global/international market". Japan is 95%+ ethnic japanese, and this makes it a complete different ballgame. If you've never been, learning how the culture works (what makes a "salaryman" a "salaryman"). Funnily enough, if you're a huge company (FB, Google, etc), then you actually CAN treat japan as just another global/international market, because name recognition has already pierced the japanese public and if the association is good (fashionable/smart/innovative/trend-setting foreign brand) then they'll buy what you're selling without much thought.

- Fiber is very cheap and accessible, the intra-country connections are blazing fast, but the connections to the outside world (like the USA) can be slow.

- The NHK fee is a thing, look it up and decide what you want to do before you come over (I wish someone had told me).

- Conglomerates are a huge thing in Japan, there are virtually no anti-trust laws. Companies like Toyota or Yamaha get their fingers in almost everything in Japan.

- Building trust as a company in japan takes a long time, but is even easier if you seem like a "japanese" company. I'm almost 100% sure that LINE has come as far as it has because people thought it was a japanese company at the beginning (https://en.wikipedia.org/wiki/Line_(software)#History).

- This startup program looks most enticing for big established companies that want to create a japanese entity. Why would a company need to do that? because Japan's market is completely different, and often just making a branch office won't work.

- If you have 50K you can get into japan relatively scot-free by getting an investor visa, and likely fast-tracking yourself to a status called "Highly Skilled Professional" with the right job, which can lead to a "permanent resident" visa (you never become a citizen if you're not japanese).

- The most important thing I can tell you about japan is that it's greatest strength is it's greatest weakness: just about everyone is in the same "lane". When you leave that lane, things get extremely difficult, but if you stay in the lane, everything is smooth and easy. The lane includes things like politeness-by-default, general honesty & propriety, but also includes overly-intense-sometimes-blinding-nationalism (nationalism != patriotism).

There's a lot more I could say, but this list is plenty long (and random) already.

Small plug for myself -- I'm the CTO of an exceptionally small "startup"/consultancy: https://gaisma.co.jp (the homepage is in japanese and pretty skint but we mostly write software). If you've got questions about how I got to Japan or how it is, or you've got some cool projects for me to undertake, feel free to get in touch (see my profile or the gaisma page) vados@gaisma.co.jp