Japanese eggplant, also known as nasu in Japanese, is a smaller and more slender version of the more familiar western style of eggplant. Its colour is also a paler purple, with some streaks of white near the top. The skin and seeds can be all eaten.
When purchasing nasu, try looking for firmer ones that aren’t wrinkled. Their colour should be uniform. Often sold in Oriental supermarkets, it may also be found under the name of Chinese eggplant.
Some simple recipes can be made with nasu. One is to simply cut the nasu lengthwise, without removing the ends, and lightly scoring the skin with a knife. Place on a hot grill until the flesh is tender, then remove and peel the skin (which is why scoring it will help you with this part). Be careful when peeling, because the eggplant will be extremely hot!
Then, top with katsuobushi (bonito fish flakes) and serve immediately. Pour a bit of soy sauce over it.
Another recipe is nasu no itame, which can be found on this site as well.