Shopping in Japan

While i was in Japan i noticed when i bought things instead of giving the money to the shop assistant, i had to place my money on a small square tray, the assistant would then pick my money up and hand me my change. Why does this happen?

I don't understand why you say 'why'...that's so doubtful?
Apart from that, I can tell you the story. It may be a special thought of Japan, shop assistants should show them appreciation to customers. They show some respect to money customers pay. And receiving them directly by hands is considered *rude*, if to make a big thing of it. In supermarkets or convenience stores , assistants receive money by hands but not by one-hand. They receive them two-handed instead of using trays.
Other reasons would be expected. If you hand money directly to them, they'd drop some coins. Or, putting them on a tray, they can recognize its amount easily compared with putting them on a counter.
One thing I can't understand is that the assistant gave you back changes by own hands. Not using a tray?

BTW many reasons would be thought. I can't remember of this issue in other countries. Don't you do this usually?
Sorry for no-good explanation.

It's just how it's always been done here. One reason as above is that it's easier to see how much money has been paid if it is in a tray rather than in your hand, and easier to pick up from a tray than the counter. Some shop assistants will put the change in your hand- usually very carefully! Others will put it in a tray to return it to you.

if you are white or black (or any non asian race) cashiers seem to just hand money to you (carefully) rather than put it in a tray (unless there are a TON of coins). i think a lot of them get kind of used to westerner's methods of money handling.

it is something to admire. even young people here handle money better than they do back home. it would be a manager's dream back in the west to have cash handlers this good.

I tend to think it is because they (cashiers) don't want to touch your hands. However, at a few shops I go to, when they give me change, if I hold out my hand, they will set the bills on my palm and sort of drop the coins into it too.