Chirashi Sushi (we call it Chirashizushi in Japan) is a type of sushi. Although sushi is often misunderstood as just nigiri (a small block of rice topped with a piece of raw fish) or those interestingly named rolls in the US, there are actually many types of sushi in Japan.
Chirashi, also called chirashizushi (ちらし寿司) is one of my favorite Japanese meals. The word "chirashi" means "scattered," so this is basically a big bowl of rice mixed with fish, vegetables, and additional ingredients of your choice.