Unagi — freshwater eel, grilled and glazed in a sweet-savory sauce — is one of Japan’s most prized summer foods and one of its most surprising for first-time visitors. The idea of eating eel can give some travelers pause, but one bite of properly prepared unagi, with its smoky char, rich fat, and tender, almost custardy texture, usually wins people over immediately.

A Dish Rooted in Tradition

Unagi has been eaten in Japan for over a thousand years, but it became closely associated with summer thanks to a clever piece of Edo-period marketing: eel was traditionally thought to help people cope with the exhausting heat and humidity of Japanese summers, rich in protein and vitamins at a time when appetites tend to fade. Today, eating unagi on Doyo no Ushi no Hi (the “Day of the Ox,” a specific day in midsummer) remains a nationwide custom, with unagi restaurants seeing their busiest day of the year.

How Unagi Is Prepared

Preparing unagi properly takes years to master, and the process differs noticeably between regions:

• Splitting and deboning — the live eel is skillfully butterflied and deboned by hand, a skill traditionally said to take years to learn
• Kabayaki style — the eel is skewered, grilled, and repeatedly dipped in a sweet soy-based sauce (tare) made from soy sauce, mirin, and sugar, building up layers of glaze with each pass over the grill
• Regional differences — in the Kanto (Tokyo) region, eel is typically steamed before grilling, producing a softer, more delicate texture; in the Kansai (Osaka) region, it’s usually grilled directly without steaming, giving it a crisper, firmer bite

The result is a glistening, deep-brown fillet with a distinctive sweet-savory aroma that’s instantly recognizable.

Classic Ways Unagi Is Served

Unagi is most commonly served over rice, in a few standard formats:

• Unaju — grilled eel served in a lacquered box over rice, often considered the more formal presentation
• Unadon — the same idea served in a rice bowl rather than a box, slightly more casual
• Hitsumabushi — a Nagoya specialty where the eel is chopped and served over rice, meant to be eaten three different ways: plain, with condiments like nori and wasabi, and finally with dashi broth poured over it like a light soup

Pickled vegetables and a bowl of clear soup (often made with eel liver) are the traditional accompaniments.

Why Unagi Can Be Expensive

Unagi is often one of the pricier items on a Japanese menu, for a few genuine reasons:

• Eel cannot currently be fully farmed through its whole life cycle, so supply depends partly on wild-caught juvenile eels (glass eels), which fluctuate in availability
• Preparation is highly skilled and labor-intensive, often requiring years of training
• Demand spikes sharply around the midsummer Day of the Ox tradition

Because of these supply pressures, eel populations have also become a conservation concern, and some unagi restaurants and suppliers now highlight more sustainably sourced options.

Where to Try It

Dedicated unagi restaurants, often recognizable by the smoky smell of grilling eel drifting into the street, are the best place to experience it properly — some have been run by the same family for generations, slow-grilling eel over charcoal using a sauce recipe that’s been topped up and reused for decades. Unagi also appears in department store food halls and bento boxes, though the quality and price point vary significantly from a traditional specialty restaurant.

A Dish Worth the Splurge

Unagi isn’t an everyday meal for most people in Japan either — it’s a dish reserved for special occasions, celebrations, and that one midsummer tradition. For travelers willing to spend a bit more, a proper sit-down meal at an established unagi restaurant offers a genuine taste of a food tradition that’s been refined in Japan for centuries.

While global epicureans frequently queue for hours outside the commercialized, packed eel restaurants of central Tokyo, those with a deeper understanding of Japan’s culinary geography head slightly north. The Urawa district in Saitama Prefecture is historically celebrated as a sacred birthplace of Edo-style Unagi (freshwater eel) culture, dating back to the Edo Period when it served as a vital station town along the historic Nakasendo highway. At the absolute vanguard of this local heritage is Yamasakiya. Established in 1848 (the Kaei Era), this legendary establishment has spent nearly two centuries perfecting a singular, sublime craft, offering international travelers an elite, culturally authentic dining destination.

The Soul of 1848: The Infinite Lineage of the Secret Sauce

What places Yamasakiya in a completely separate league from modern dining establishments is its living history, embodied in its proprietary Tare (secret basting sauce). For nearly 180 years, through tectonic cultural shifts and modernizations, the restaurant has continuously replenished and guarded this dark, glossy elixir.

Every eel prepared at Yamasakiya is dipped repeatedly into this multi-generational sauce during the final stages of roasting. The natural fats and juices from hundreds of thousands of premium eels over nearly two centuries have melted into the mixture, creating an incredibly complex, deep, and savory umami profile balanced with a delicate, non-cloying sweetness. It is a profound flavor depth that simply cannot be synthesized by synthetic ingredients or modern industrial kitchens.

The Artisan Triad: Splitting, Steaming, and Charcoal Roasting

Yamasakiya adheres rigorously to the absolute peak of traditional Kanto (Edo-style) unagi craftsmanship, a methodology perfectly summarized by the old Japanese culinary proverb: “Three years to learn filleting, eight years to master skewering, and a lifetime to perfect roasting.”

The culinary workflow is executed with mathematical precision:

• The Precise Cut: The premium eel is carefully split from the back, honoring the Edo samurai tradition of avoiding a belly-cut, which was associated with ritual suicide.
• The Softening Steam: The skewered fish is thoroughly steamed before hitting the fire. This vital step melts away excess, heavy fats while locking in moisture, rendering the texture unbelievably fluffy, delicate, and pillowy.
• The Charcoal Roasting: Finally, the eel is grilled slowly over premium Bincho-tan (white charcoal). The high, radiant heat caramelizes the secret sauce against the skin, adding a beautiful, smoky, and crisp outer shell that contrasts spectacularly with the meltingly soft interior.

Access Information

Yamasakiya is situated in Urawa, Saitama Prefecture. Positioned within a highly refined neighborhood, it is exceptionally accessible via direct, rapid train networks radiating straight out of central Tokyo hubs.

Traveler’s Note: True to elite artisan traditions, Yamasakiya prepares its meals with immense care, meaning dishes are often crafted to order. Advanced reservations are highly recommended, particularly for dinner services, to secure a seat within this historic culinary theater without unexpected wait times.

The Unaju Protocol: Dining with Reverence

When your premium Unaju (basted eel served over high-quality rice in a traditional lacquered box) arrives at your table, observing local epicurean etiquette elevates the entire experience:

• Keep the Lid Sealed: The lacquered box arrives with a matching wooden lid. Do not remove it immediately. Allow it to sit at your table for a brief moment; the trapped steam concentrates the rich aroma of the charcoal and sauce, which explodes beautifully into the air the moment you lift the cover.
• The Sansho Pepper Balance: On the table, you will find a small container of green Sansho (Japanese citrus pepper). Dust this spice sparingly and directly onto the eel flesh. The bright, numbing, and refreshing citrus top-notes cut through the rich density of the eel oils perfectly, revitalizing your palate.
• Appreciate the Clear Soup: Your meal will be accompanied by Kimosui—a clear, delicate soup containing the nutritious liver of the eel. Sip this broth between bites of the rich rice and fish to maintain a clean, balanced gastronomic rhythm.

An Indispensable Ritual of Japanese Culinary Mastery

Yamasakiya stands as an extraordinary cultural refuge, proving that the finest iterations of Japanese cuisine thrive when insulated from the frantic pace of mass global tourism. By diverting your journey to the historic streets of Urawa, you transcend ordinary commercial dining. Here, within a culinary lineage stretching proudly back to 1848, you experience the absolute pinnacle of dedication, fire, and liquid time.