Fields of sushi

Can anyone tell me why take-away packs of sushi have a strip of plastic "grass" in them? They all come with this small rectangle of plastic grass either between or next to your sushi. Does anyone really believe there is a field of sushi out there, just waiting to be freshly picked by the farmer? What does grass have to do with sushi anyway? While I'm sushi-bashing, can someone explain those take-away boxes they have for hand rolls? Why do they require a rubber band to keep them shut? Every other cultural take away makes use of boxes which shut - either by clicking into place, or with the judicious use of a LID. What is is about the Japanese, exactly, which makes them so pro-rubber band? Since I'm on a roll (a hand roll that is....*groan*) - why do they put the soy sauce into those tiny fish-shaped bottles? What clever person thought, OH, I think I'll invent this tiny fish-shaped bottle and pour some soy sauce into it, and then nestle it next to some fake grass, in a flimsy plastic box which DOES NOT CLOSE properly without a rubberband? I want to meet this person. I think there is some untapped genius there. Imagine what he or she could do with Indian food?!