Here are some references for you
soompi forums > Nail Thread
I found a whole forum on those neat Japanese-style nails.
If you just want to buy a set try Ebay.
You can use nail prints or stickers on your actual nails (though gluing stuff to your actual nails isnt very good for them) or you can buy pre-decorated fake nails to affix to your natural nails.
Digital nailart printer, nailprinter, nailpainter
TUTORIAL on creatively painting your nails.
I didnt read it so Im not much help but it LOOKS helpful (ok im lazy)
I definitely suggest making your own and if i wasnt so damn squeamish about fake nails Id definitely make a set + tutorial.
Here are some pics of Japanese style nails i found, some are ADORABLE!
