A Japanese Papaya Melon

That was different. I noticed these little "papaya melons" at one of the Japanese supermarkets here in Singapore going for S$25 (US$17). I wasn't quite sure what it was - I thought maybe it was just a papaya shaped like a small watermelon. But when I finally cut it open, it had none of that yellow papaya character. Instead, both the flesh and seeds were white, and was really just a melon. It was sweet and juicy like honeydew, but its small size made it a bit frustrating to eat. For that kind of money, I'd rather just go the whole nine yards and get an entire melon. Was there supposed to be more to this?