Among the fish used as sushi toppings (neta), "Hikarimono" refers to fish with a bluish color on the back and shiny silver on the belly. Examples include mackerel (saba), horse mackerel (aji), gizzard shad (kohada), sillago (kisu), sardine (iwashi), Pacific saury (sanma), and halfbeak (sayori).
These fish are known to be delicate and perish quickly once out of the water, making storage and live distribution difficult.
Because of their strong smell, they are often marinated in vinegar (shime) and served with aromatic condiments such as shiso leaves, pickled ginger, wasabi, or chopped green scallions (menegi) to enhance the flavor.