Kabocha is a winter squash very similar to pumpkin or butternut squash. The main difference, aside from the appearance, is that the flesh, when cooked, doesn't soak as much liquid and remains dry. This works well for stews and purees.
Dominicans use a type of kabocha called auyama. Auyama is loved in the Dominican Republic and is used in many dishes, from soups to stews, cooked with beans and meats, or simply boiled or pureed. When pureed, the dish is called mazamorra.