Part of the reason why 'Japan: the land of clean and rubbish free' is so clean and rubbish free is because people tend not to eat on the streets. If you buy food, you either eat it where you bought it or you tuck it away in your bag and wait until your arse gets home. Because of this, there are minimal bins on the streets. A culture shock for a London boy like me who is used to people using the road as their nearest and dearest place to lob their rubbish - despite bins being lined up along the street. When you and your gaijin posse decide to do the Western thing and stuff your face full of that McD's you'd bought 2 minutes ago as you stomp the sidewalk, your trek along the street soon turns into a scavenge hunt for a bin 3 blocks later. Bins are scarce. And even when you do find a bin, chances are you can't put your rubbish in it, because it's exclusively for a particular kind of rubbish.
To begin with it gets annoying, but you soon learn the Japanese way and eat your food where you bought it or you tuck it away in your bag and wait until your arse gets home. What could've grown into a great annoyance was absolutely fine with me. It kept the streets clean. People in other countries where littering is rampant should take note.