You can certainly get into the nitty-gritty details of sushi and sashimi to understand differences between the two, but ...

Sashimi refers to thinly sliced raw fish, served without rice. The slices are typically arranged on a bed of thin threads of ...

Then not much soy sauce. So these are the three ways: sashimi, nigiri, and roll. Nigiri sushi. Make half-turn, take the chopstick and put soy sauce on the fish side. You can see no rice.