[akx]

How about a plain box in some relevant color (sakura blossom pink? :) ), hand-stamped with the Candy Japan logo?

In my mind's eye, that'd remain classy enough not to be creepy/cringy/embarrassing (as https://news.ycombinator.com/item?id=11641715 complains), but would also have sort of a personal touch to it.

Having a couple rubber stamps made and stamping each box during packaging wouldn't probably cost an awful lot...

[bemmu]

Seems like a good alternative. There has been a lot of valuable feedback in these comments. I hadn't considered how these might be perceived at a workplace, or that people even receive packages at work.

[alphonsegaston]

I second having something more classy. Japan is renowned for its package design, so why not include this aspect as part of what's being sold? Maybe something like how Meiji brands their goods. That illustration/design would seem to me to make you less differentiated from your competitors who are tacking on candy to their other "nerd culture" offerings.

[konschubert]

It would probably be cheaper AND would feel more "authentic".

After all, his main edge over the local japanese stores is authenticity. The fact that it comes "directly" from Japan.