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Story vol.13
21, Aug 2026
Expressing the rich bounty nurtured by Hayama’s sea and surrounding land in its most exquisite form upon the plate, as the seasons shift—this is the core culinary philosophy cherished by Casa CABaN HAYAMA. One of the summer ingredients that symbolizes this approach is “Hayama Uni” (sea urchin), featured in both the Main Dining and our Japanese restaurant Ashitaba. Boasting a rich, briny flavor and a melt-in-your-mouth texture, this delicacy also offers a solution to a marine environmental issue facing the seas of Hayama.
Did you know that due to the disruption of the ecological balance caused by factors such as global warming, an abnormal proliferation of sea urchins is occurring in waters across Japan? The seas of Hayama are no exception. Sea urchins are remarkably resilient creatures with lifespans exceeding ten years, capable of enduring prolonged starvation. When large populations of sea urchins devour underwater seaweed right down to the base, it leads to ocean desertification—a serious situation where various marine creatures lose their spawning grounds and habitats, threatening the natural ecosystem with collapse.
“Because these overabundant sea urchins have consumed all the seaweed, they contain almost no meat. As a result, they couldn’t be sold as food, and the costs of culling and disposal were also high, creating a severe dilemma,” explains Chiharu Kubota of Kubota Marine Farm. With the goal of finding a practical use for these sea urchins, Mr. Kubota launched a joint research project with Shinnase Fishing Port. By harvesting the sea urchins that were overpopulating the rocky shores, transferring them to specialized pens, and feeding them a high-quality diet, they established a cultivation technique to produce flavorful roe —successfully branding the result as “Hayama Uni” (Hayama Sea Urchin). “It was a relentless process of trial and error,” Mr. Kubota recalls. “If we packed them into the pens too densely, they’d die; if we overfed them, the feed would rot. They’re so resilient out in the open ocean, but when you try to raise them by hand, they turn out to be surprisingly delicate.”
Hayama Uni (sea urchins) grow by feeding on Hayama’s wakame seaweed and kelp inside the specialized pens.
The flavor of sea urchins is greatly influenced by what they eat. While artificial feed is standard practice in aquaculture, Kubota Marine Farm is committed to using only natural sources, giving their sea urchins an exclusive diet of wakame seaweed and kelp harvested locally in Hayama. Furthermore, they process the sea urchins completely free of alum—a food additive often used during processing to preserve color. Mr. Kubota aimed to perfect a farming method that brings out the natural flavor of sea urchins. He commuted tirelessly from his home in Tokyo to Hayama for six months. Day by day, he cultivated deep bonds of trust with local fishermen, the fishery cooperatives, and municipal authorities to enlist their support. His passion and commitment to quality eventually caught the attention of chefs across Japan.
Hayama Uni (sea urchin) fills the palate with a rich, robust umami flavor, the very essence of Hayama’s seas.
Chef Takeda of the Main Dining is among those who resonated with Mr. Kubota’s passion. “‘Hayama Uni’ (sea urchin) is a wonderful ingredient with a concentrated sweetness,” says Chef Takeda. “Since its flavor is already perfect, we don’t add anything extra—we simply craft dishes that let guests savor the sea urchin itself.” Head Chef Ando of the Japanese restaurant Ashitaba adds: “While many people associate sea urchin with Hokkaido, if we can source such high-quality sea urchin from the sea right in front of us, there is every reason to embrace it.”
The story of “Hayama Uni” doesn’t end on the plate. After the meat is extracted, the remaining shells are sun-dried and transported to farms that grow organic vegetables across the Miura Peninsula, where they are reborn as organic compost.
“Hayama Uni” stemmed from a sincere desire to address a challenge facing the waters of Hayama, and has since been transformed into a supreme culinary ingredient. Nurtured by the waters of Hayama, nourishing our guests, and ultimately returning to the earth, “Hayama Uni” tells a profound narrative of nature’s endless cycle connected to the ocean.
Main Dining appetizer: Chilled Miura corn soup paired with Hayama Uni (sea urchin) and Fujisawa cherry tomatoes
Pasta from the Main Dining: Fedelini with Hayama Uni (sea urchin)
Seasonal Chakin-shibori served at Ashitaba: Hayama Uni (sea urchin) temari sushi topped with kudzu glaze