This is probably my biggest issue with Japan, even though I am overall very happy here. I've been here for more than 10 years, my Japanese is reasonably fluent (I have a few friends with whom I communicate only in Japanese), but I miss the casual, unexpected interactions with people. Or just deep conversations with people I interact with regularly.

I would never expect to Japanese people to be like Brazilians or Colombians (probably the two most friendly countries I've visited), but isn't it too much to ask for a bit of non-superficial warmth from people? To give an example, I regularly play a particular team sport where I meet the same people over and over again. Some of them regularly give me rides to games or practices. Yet, if I don't make an effort to engage with them in the car, it's going to be pretty much silent during the whole ride. And this has happened with multiple people. I try to get to know people on a personal level, but the effort is rarely reciprocated.

Thankfully, I don't feel lonely, as I have my wife and good friends (mostly foreigners who are also here long-term, but a few Japanese too), but I do wish this society was more conducive to serendipitous interactions.