I lived in Tokyo nearly 7 years and moved home around 12 years ago. A lot has happened, I have a wife and a kid now and honestly, not a day goes by I don't think about Japan.
Do any young people or people who arrived in Japan relatively recently post here? I get the feeling it's longer-termers, which is great also, just curious.
Anyway, if you live there, enjoy and live it up.
It could be anything. If I wanna meet up with friends for drinks, this city is such that you're probably looking at a $30 Uber each way if you wanna avoid driving, not to mention a round of drinks these days can easily be $80 w/ tip. There is plenty that can be annoying in either country and it's probably best not to overthink it. I don't actively wish I lived in Japan, but having lived there for a while and having moved back leaves me this convenient outlet to bitch about nearly anything by thinking to myself "Well, in Japan..." but of course that isn't really fair.
I will say at a minimum a city you can walk around in safely at night with everything open and essentially no crime is really something.
Here if you're on a side street (the huge majority of the city) and you get mugged the police are pretty much like well yeah, that happens. And I'm a guy. I can't imagine being a woman trying to walk to a car after dark on a regular basis. Fucking shitshow but hey, freedom.
ETA - good to see that 8 years ago I was posting about pretty much the exact same thing.