Kabocha Squash

Kabocha is a type of squash found in Japan. I think some people also call it "Japanese pumpkin." Kabocha has an extremely hard green exterior, but inside is yellow-orange colored and tastes very sweet. If you've ever had tempura before, the chances are you've eaten kabocha before. Other than tempura, it's commonly used for nimono (simmered in soy sauce, sake and mirin) in Japan.
Although it's smaller than American pumpkins (it's about 6 to 10 inches in diameter), if you don't have a large family, it can be difficult to finish the whole kabocha. If you are lucky, you may be able to get the half cut size at the grocery store, but chances are slim. Plus, once the kabocha is cut open, it can grow mold fairly easily.
The best way is to cut them up in pieces, and freeze it. There are a couple of ways you can cut kabocha pumpkin. The exterior is extremely tough, so be careful when you cut it. I recommend using a knife with jagged edge (like a steak knife). First, I cut the kabocha in half, and scoop out the seeds from the inside (as you would do to melons). I normally cut kabocha into two different cuts.
Crescent-Cut: Like the name suggests, it looks like a crescent moon. Each slices should be less than half-inch thick, and 3 to 4 inches long. This cut is ideal for tempura, squash & bacon, or miso soup (cut one of these slices into much tinier pieces). Be sure to cut off the green exterior. It's much easier to cut those off once you cut kabocha into these smaller pieces.
Chunky-Cut: Another common cut is the chunky cut. Each pieces should be about an inch and half to 2 inches thick/long. These thicker chunkier pieces are ideal for nimono. Again, cut off the green exterior skin.

Normally I put about 10 pieces/slices into a baggie, and put those baggies into a big ziplock bag, and stick that into a freezer.

From one normal sized kabocha, you could probably get at least two bags of each cuts (with about 10 pieces). They are sweet and tasty, so I highly recommend trying them. Just remember to be careful when you cut them!