Shirako is a Japanese specialty consisting of cod's milt, or sperm sacs. It is characterized by its unusual visual appearance and a creamy, buttery flavor. Traditionally, shirako is served either raw or slightly grilled, and it is recommended to consume it when it's as fresh as possible.

Shirako is often poached with ponzu sauce, or tempura-fried with yuzu kosho condiment on the side. The word shirako means white children, and the ingredient is in season during winter. Although shirako is an acquired taste, it is served in restaurants all over Japan.

Fugu is the Japanese word for a fish known as pufferfish, blowfish, or globefish. The fish is infamous for its poisonous parts that contain the lethal poison tetrodotoxin, highly concentrated in the liver, ovaries, eyes, and skin. Trained chefs who want to prepare fugu must undergo scrutinized testing and licensing that is done at local government level.

However, some people prefer the light numbing sensation that the fugu toxin produces, so they ask the chefs to serve them small parts of the toxic organs. In Japan, fugu is usually consumed in specialized restaurants that serve a complete meal which typically includes several courses of the fish served in varying ways, such as fugu sashimi, boiled fugu chiri, fugu rice porridge, or deep-fried fugu. 

Kazunoko is a Japanese term for salted herring roe that is typically marinated in dashi stock. This yellow roe is slightly elongated and filled with tiny round eggs that pop and release their briny flavor when eaten. In Japan, herring roe is usually first desalted and then marinated in dashi stock, which is often seasoned with soy sauce, kelp (seaweed), and bonito flakes.

The word translates as number (kazu) and child (ko), and the dish symbolizes a prosperous future and fertility. Because of this, kazunoko is one of the essential courses served during Japanese New Year festivities—collectively called Osechi-ryōri. 

Surimi, meaning ground meat in Japanese, is a Japanese fish product made by grinding the meat of gutted, filleted, and cleaned fish to a smooth paste, which is then treated with cryoprotectants before it is frozen. A staple of traditional Asian cuisine, this product is distinguished by an absence of scent and creamy white color, and it is commonly prepared with the flesh of fish such as Alaska pollock, threadfin bream, blue hake, blue whiting, jack mackerel, and sardine.

The fish paste used to be traditionally made by hand, but the method of freezing the paste has given rise to the industrialized version. Although Japan has been considered the leading country of surimi production worldwide, these days this versatile fish paste is widely produced in many other countries around the world, including Vietnam, Korea, Thailand, China, New Zealand, and the US.

Narutomaki or naruto is a traditional type of fish cake and a type of kamaboko (cured fish surimi) that’s most commonly used as ramen topping. It’s made by wrapping white fish paste (surimi) that’s been colored with red food dye around undyed fish paste.

The combination is rolled into a log, steamed until solid, then cut into thin slices. On the cross-section, there is a spiral after which it was named because it’s reminiscent of the famous Naruto whirlpools which appear between Shikoku and Awaji Island. 

Tobiko is a Japanese term for flying fish roe. The natural color of this roe is bright orange, but sometimes other ingredients, such as squid ink or yuzu, can be added to impart the roe with various colors and slightly alter its flavor.

Tobiko eggs are smaller than ikura (salmon roe), but they have a similar crunchy texture. Their flavor is often described as salty, smoky, and subtly sweet. Tobiko can be enjoyed on its own, but it is mostly used as an ingredient in gunkan sushi or as a garnish on various sushi rolls.

Masago is a Japanese term for the capelin roe (Mallotus villosus). The roe usually has small, pale-colored beads, and producers frequently dye it red, black, green (wasabi), or yellow (yuzu). Masago is usually cheaper than similar roe varieties, such as ikura (salmon) or tobiko (flying fish).

It usually has a milder flavor and less crunch, so it is best used as a garnish or paired with neutral-flavored dishes. The most common use of masago is as a sushi garnish—usually as a topping for rolls or hand-rolled sushi. It is often falsely marketed as the slightly more esteemed tobiko.

Readily available across the country, these colorful Japanese fish cakes are made with puréed white seawater fish meat called surimi which is typically formed into a loaf-like shape, steamed on wooden boards until fully cooked, and it is then sliced before serving. Kamaboko is typically enjoyed with various dipping sauces or included in hot soups and noodle dishes.

Kamaboko cakes are also a popular gift item and an essential part of osechi-ryōri, traditional Japanese New Year foods. One of the most popular kamaboko varieties is narutomaki, known for its pink or red spiral pattern which represents the impressive Japanese Naruto tidal whirlpools.