Kabocha salads are generally made with mayonnaise or yogurt... but I prefer heavy cream. It highlights the flavor of kabocha squash.
When I made the salad with mayonnaise or yogurt, it was a bit too tart for me. I liked it with heavy cream.
You should adjust the seasoning according to the size of kabocha squash. For the heavy cream, I recommend 35% milk fat heavy cream.
Enjoy Japanese food around the world.