It's also useful to remember that the general lack of public trash bins isn't a long-standing part of Japanese culture: it only dates to the 1990s, when public

It's also useful to remember that the general lack of public trash bins isn't a long-standing part of Japanese culture: it only dates to the 1990s, when public trash bins were used for the infamous Sarin gas attack. After that, most bins in cities were removed. What's cultural is what happened later: the cities didn't turn into trash heaps, because people simply took their trash home or otherwise waited to find a suitable place to dispose of it.