How to ask for something to be wrapped.

Last time I was in Japan I bought some sake cups and the cashier put all the glass cups together in the plastic bag. I wanted to ask her to wrap them in paper to keep them from breaking, but I couldn't think of how to ask (somehow I got her to understand).

My first thought was "wrappu kudasai", but I'm not sure if that's right. How should I ask this in the future when buying breakable things?

"rappu kudasai" may sound like you're asking for a cling film. ;)

You can say "kowarenai youni tsutsunde kudasai" (please wrap them up so that they won't get broken).

Mikazuki,

You have already had your question answered, but I don't recall ever having had to ask in Japan. Even in 100-yen shops, the cashier will wrap glass and breakables in newspaper without being asked, so I am surprised to hear about your experience.

she was going to do it anyways, but while she was in the middle of her business you told her to wrap them when she was already going to do it.
I've done it lots of times before. I've learned to just wait it out until she finishes and then ask her for something I need.

Actually, it was at a 100 yen store. I know she wasn't going to wrap it because she already took the next customer. I waited until she was done before asking her.

I was pretty surprised too because they usually wrap/box everything. Maybe she just forgot.

. . . 100 yen stores I've been in supply the wrapping paper so you can do it yourself.

At tourist gift shops, they automatically wrap stuff with decorative paper, assuming it may be a gift or omiage.

100 yen shops are usually self service as far as wrapping goes. At any 100 yen shop I have ever been to there is a bench near the counter where there is a box of newspapers that you can use to wrap stuff. At a shop as cheap as that you can't really expect to have items wrapped for you.