ShoeInk
Japan's case is really simple, you see, socialising is a skill gained from experience, not from sitting in front of your laptop watching people socialize, it doesn't work that way.
So we have a dude who's, let's say, socially awkward, and this dude doesn't interact with people and thus they're unable to get hold of this skill. This dude then becomes afraid of interacting with people, and from some failures in interacting with people, they develop inferiority complex. They shut themselves watching or reading whatever, thinking that they can learn something, but in reality, when it's show time, all their preparations flies away with the wind, resulting in them having yet another failed interaction. So they become even more depressed, in the end, they visit this forest nearby and the next day, 'friends' and family visit their grave.
This is quite specific, but a bit of tinkering will prove that the rest of the cases are similar.
Yours truly,
Nothing came to mind