Citizenship gives you full rights. You can vote, you can’t be deported from the country, you are a Japanese citizen. To qualify for this you need to live and work in the country for five years.
Permanent residency is like citizenship but not as many rights. You don’t necessarily need a job to stay in the country, we promise not to kick you out…unless you do something blatantly anti-social (crime). To qualify for these reduced rights takes…ten years. Twice as long as citizenship would.
But part of the deal with citizenship is you renounce your other nationalities and really commit to becoming Japanese. The government will send a representative to inspect your life; your apartment and social circle, and make sure you are sufficiently integrated. But if you’re willing to commit to Japan, they’re willing to have you after just five years.
But if you’ve been living there for years and still don’t want to commit to the community, they will begrudgingly give you PR, but they’ll make you wait twice as long in protest.
It’s a tough system, but it’s incredibly effective at protecting their cultural values that enables things like Tokyo to exist.
For what it’s worth, while I’ve experienced my fair share of racism there, I’ve also been embraced far more than I’ve been rejected.
I remember eating at the Michelin 3-star sushi restaurant of a famous chef who became infamous for how he was treating/refusing to serve some foreigners. Just getting a reservation as a foreigner was insanity.
But when I showed up (in a new suit, no less) and spoke with him, he kept us by the bar chatting with him all night. He just struggled dealing with non-culturally Japanese people come in, not understand what he was trying to do, and destroying the atmosphere he was dedicating his life to creating.
I knew the rules, and he was an incredibly gracious host to me and my guest as a result.
Japan is far more xenophobic than it is racist, but they’re more so xenophilic once you get a drink into them ;)