Kabocha is sometimes also known as Japanese Pumpkin and it's C. maxima, not C. pepo. Not sure what Japanese Pie Pumpkin is, but most pie pumpkins (various cultivars) that I've seen are orange and weigh less than 5 lbs.

There is a Japanese Pie Pumpkin, which has several alternate names: "An heirloom variety. Beautiful 12 lb. black fruit have creamy white flesh. Samuel Wilson, Mechanicsville, Pennsylvania, introduced this variety in 1884, and it quickly became popular because of its novelty and advertising. The seeds are "curiously marked or sculptured in the manner of Chinese letters." The unique-looking seed led to it being called Chinese Alphabet squash." It is also known as Nippon Island. It is a C. mixta, Cushaw group.

Thanks for the info. I still need to open the packet and look at the seeds to see if its the Nippon Squash / Pumpkin.