The Sanriku Coast of northeastern Japan is famous for its rich marine resources, nourished by cold ocean currents and nutrient-rich waters. Among its many distinctive seafood specialties is maboya, a type of sea squirt known for its unusual appearance, complex flavor, and rich nutritional content.
Often nicknamed the “pineapple of the sea” because of its rough, pineapple-like appearance, maboya is a delicacy with a flavor unlike most other seafood. Its distinctive taste can combine all five basic sensations of sweetness, saltiness, bitterness, sourness, and umami, creating a remarkably complex experience that many seafood enthusiasts never forget.
Miyagi Prefecture is one of Japan’s major producers of sea squirts, accounting for approximately 70–80% of domestic production. Maboya cultivated along the Sanriku Coast grows slowly in clean, nutrient-rich seawater, feeding mainly on abundant plankton.
It takes approximately three to four years for maboya to reach maturity. A fully grown specimen can reach around 15 centimeters in length and 10 centimeters in diameter.
The main season for maboya in Miyagi is generally from May through August. During this period, the sea squirts develop thick, flavorful flesh with a particularly appealing balance of sweetness and umami.
Maboya harvested in its peak season is also known for its high glycogen content. It can contain more than seven times the amount found during winter, making the summer season an especially popular time to enjoy this local delicacy.
Fresh maboya can be enjoyed in many forms, including sashimi, vinegared dishes, and clear soups, allowing visitors to experience its distinctive flavor in different ways.
Maboya contains a variety of nutrients, including minerals, selenium, taurine, glycogen, and iron. These nutrients contribute to normal bodily functions and are one reason sea squirt has attracted attention as a nutritious seafood.
Because of its combination of distinctive flavor and nutritional components, maboya is sometimes described as a kind of “nutritional capsule from the sea.” For travelers interested in Japanese seafood culture, it offers an opportunity to discover a food that is both unusual and deeply connected to the local marine environment.
Sea squirts belong to the class Ascidiacea within the subphylum Tunicata. More than 2,000 species are known worldwide.
During their larval stage, sea squirts resemble tiny tadpoles and possess characteristics of chordates, including a dorsal nerve cord and notochord. As they mature, they attach themselves permanently to rocks or other surfaces on the seafloor.
This dramatic transformation—from a free-swimming, tadpole-like larva to an immobile adult—is one of the most fascinating aspects of their biology. Sea squirts are therefore also of interest from a scientific and research perspective.
Sea squirts are found throughout the world’s oceans, from shallow subtidal areas to deep-sea environments. Many species live attached to surfaces, while some occur in groups or colonies.
They mainly feed by filtering phytoplankton and tiny particles of organic matter known as detritus from seawater. In this way, sea squirts also play a role in the marine ecosystem by filtering water as they feed.
The Japanese name hoya is traditionally said to be associated with its resemblance to the hoya, or protective covering around the flame of an old Japanese-style lamp. Another explanation connects the name with its resemblance to the parasitic mistletoe plant.
Maboya’s distinctive shape also inspired the nickname “pineapple of the sea,” a name that makes sense once you see its rough, spiky exterior.
The two main species of sea squirt commonly eaten in Japan are maboya (Halocynthia roretzi) and akaboya (Halocynthia aurantium).
Sea squirt is particularly popular along the Sanriku Coast of the Tohoku region. Ishinomaki Fishing Port in Miyagi is one of the region’s important distribution centers. Sea squirt is also eaten in Hokkaido, although akaboya is less widely distributed.
Maboya can be prepared in many different ways. Popular preparations include sashimi, vinegared dishes, grilled sea squirt, fried dishes, shiokara, and dried sea squirt.
One particularly distinctive preparation is bakurai, a salted and fermented sea squirt delicacy. It is especially popular as a snack to accompany Japanese sake and is prized for its concentrated marine flavor.
When maboya is extremely fresh, it has little unpleasant odor. Instead, it offers a subtle sweetness followed by a distinctive ocean aroma. This fresh flavor is one of the reasons it is particularly appreciated by seafood lovers.
The internal organs, known as the wata, contain much of the characteristic aroma associated with sea squirt. Some experienced fans specifically enjoy this intense, briny flavor.
For those who prefer a milder taste, removing the wata and rinsing the flesh with the liquid found inside the sea squirt, often called hoya water, can help reduce the stronger aromas.
There is also a traditional way of enjoying it that is considered a favorite among connoisseurs: mixing the internal organs into the hoya water and eating them together with the flesh. This brings out an especially rich and intensely marine flavor.
For visitors traveling along the Sanriku Coast, tasting maboya is an excellent way to experience the region’s seafood culture. Coastal towns such as Ishinomaki, Kesennuma, and Onagawa have restaurants, seafood shops, and izakaya where seasonal maboya may be served.
Eating fresh seafood close to the ports where it is landed adds a special dimension to a trip. Travelers can combine sightseeing along the Pacific coast with the chance to discover one of northeastern Japan’s most distinctive delicacies.
Sashimi: Fresh maboya is sliced and served simply, often with wasabi and soy sauce or ponzu. This preparation allows its natural sweetness and ocean aroma to shine.
Vinegared Maboya: A light vinegar dressing adds refreshing acidity and helps highlight the sea squirt’s natural sweetness.
Clear Soup: Maboya can be served in a delicate Japanese clear soup, where its subtle marine aroma blends with the broth.
Bakurai: The salted and fermented preparation offers an intense, concentrated flavor and is especially well suited as a snack with Japanese sake.
Maboya is one of the Sanriku Coast’s most distinctive seafood treasures. Its unusual appearance, complex five-flavor profile, and nutritional characteristics make it very different from familiar shellfish and fish.
The best way to appreciate maboya is to try it fresh during its May-to-August season, when the flesh is thick and flavorful. Whether enjoyed as sashimi, in a vinegared dish, in soup, or as bakurai, each preparation reveals a different side of this unusual delicacy.
If you are traveling through Miyagi and the Sanriku Coast, be sure to look for locally caught maboya at seafood restaurants and port towns. Tasting the “pineapple of the sea” is a memorable way to experience the distinctive flavors and rich marine culture of northeastern Japan.