What is there to integrate into? Adult life is mostly just going to work to pay the bills. I don't know anyone with a particularly interesting life outside of their job. Most Japanese people aren't going to be any less apathetic about a foreigner than others of their own group. Naturally there will be more traction with those looking for free English teachers and gaijin hunters. What a larger proportion of people lik…
If you want to be respected (but not 'integrate') as a foreigner by traditional society in Japan it's good to work at a prestigious place where there are few Japanese people such as an embassy. Failing that a gaishikei company that sounds foreign to people who don't know better but isn't (likely >90% Japanese). Or just be rich (this may also involve being very picky or completely averse to working with the native pop…
Don't even expect the drinks after work culture, a lot of that has disappeared. It was a thing when people actually had hopes that showing loyalty to a company would improve their lives.
If you want to enjoy life just watch videos of expats chilling in places Thailand for inspiration. Otherwise you may become like the Japanese people and end up bored and wanting to leave.