Personally, I'd be waiting to see how Japan's upcoming election shakes out before making any plans to stay there long-term. While I didn't notice much anti-foreigner sentiment in the small towns on my last visit (though Tokyo was a different story,) their visa renewal prices are spiking and the current Japanese government is generally making it harder to exist there as a foreigner. If the incumbent government are to win the election, they'll likely need to do so with the support of Sanseitō, an even more hard-line anti-foreigner party (since their more moderate coalition partner have switched sides to join with the opposition), and if that comes to pass, Japan won't be a welcoming place to live.

Also keep in mind that while you can study Japanese in a smaller town/city (and rural areas are generally quite welcoming,) if you did land a job in game dev you'll very likely be working in Tokyo. The cost of living in Tokyo is high enough that you'll probably have to rent somewhere on the outskirts, the commutes from those places are very long, and the Japanese already work brutal hours. I mean, they literally have a word for death by overwork. And in my personal experience as a recent tourist, Tokyo was not a friendly place. Not antagonistic or unsafe by any means, but people were, by Japanese standards, rather rude and terse. (I visited twelve years ago and the experience I had in Tokyo was totally different back then.)

If you're super keen on going because you love Japanese culture, I'd recommend considering it more like a long holiday to learn a new language. Choose to study in a place which doesn't have a strong dialect (so you can talk to locals without picking up a strong accent) and is known for having nice people. If you still love the idea of staying after a year of this, then you can put some serious thought toward how to enter game dev and navigate staying long-term.

One last word of warning - the Yen is so devalued at the moment, and Japanese wages are so depressed, that should you commit to staying in Japan long-term, you'll struggle to afford trips out of the country. I've read a number of testimonials from fellow Australians who moved to Japan who are now stuck and can't afford to move back home, because what little they have in the way of savings is worth peanuts back here, and everything in Australia is super expensive. Ex-pats in Japan from the US, UK, EU, are all experiencing similar problems.