Low crime rates
Japan is one of the safest countries ever. The chance of becoming a victim of a crime is several times slimmer than in the US (no surprises there). The government and media work extra-hard to enforce a safer way of living in Japan, so even schoolchildren can walk around at night without any worries.
In fact, you could leave your bag or backpack outside when going into the bathroom and not worry about it going missing. That’s just how ridiculously safe the country is! If you’re concerned about Yakuza, while they’re still alive and well, they aren’t going to go out of their way to intimidate foreigners (typically).