【Title】
What’s the Difference Between Unaju and Unadon? At Hasebe in Okazaki, the Answer Was 1.5× More Eel—and an Absurdly Hot Oshibori
So, what actually separates unaju from unadon?
An eel restaurant menu raises a deceptively simple question:
What is the difference between unadon and unaju?
The general answer is surprisingly straightforward. According to the Japan Ready-Made Meal Association, grilled eel over rice is called unadon when served in a bowl and unaju when served in a rectangular jubako box. At the most basic level, the distinction is the vessel.
Real restaurants complicate things. Some put more eel in the box version or price it higher. In other words, the dish name does not guarantee a nationwide standard for portion size.
So the menu at the main branch of Unagi no Hasebe in Okazaki provided a useful field test.
Its answer was extremely physical.
Hasebe’s answer: Matsu is 2/3 of an eel; unaju is one whole eel
At the time of the visit, the in-store menu showed:
| Menu item | Amount of eel |
|---|---|
| Unadon Matsu | 2/3 eel |
| Unaju | 1 eel |
That means the unaju contains 1.5 times as much eel as the Matsu.
Generally, “bowl versus box” explains the names. At Hasebe, however, the choices also had a clear quantity difference during this visit.
So this was not merely “pay more because the rice moved into a square box.”
The box came with more eel.
Decision made: go for the full eel.
I expected a famous restaurant to be packed. It was surprisingly quiet
Hasebe’s main branch has hundreds of reviews on restaurant-listing sites and a relatively large seating capacity.
A wait therefore seemed entirely plausible.
Instead, at the time of this visit, it was much less crowded than expected. In fact, it was pretty empty.
Excellent.
A popular restaurant is not necessarily a permanent queue generator. Crowds change with the day, time and season, so this is not a promise that the same timing will always work. But on this visit, there was no bonus event in which the customer’s patience got grilled before the eel did.
The first boss was not the eel. It was the oshibori
The first thing to make a serious impression after sitting down was the wet hand towel.
It was ridiculously hot.
This was less “please wipe your hands” and more “we have pre-steamed your hands for you.”
Before the eel reached the charcoal, the customer’s hands had already entered the heating process.
Then came the strange part: a Hasebe review from more than a decade ago also mentions a hot hand towel.
So the water heater may not simply have gone berserk on this particular day.
Is the scorching oshibori a tradition?
There is now at least a suspicion that Hasebe has been preserving not only its eel-grilling technique, but also the thermal output of its hand towels.
Then came the one-eel unaju
Matsu: 2/3 eel. Unaju: one whole eel.
Once the numbers were on the table, the choice was easy.
Unaju.
“One whole eel” is powerful information before the lid even comes off. This is a meal that attacks with a specification sheet.
This article will not invent tasting notes after the fact. Adding unobserved details about sauce, crispness or texture would turn a field report into fiction.
So only the conclusion actually recorded on site remains:
It was delicious.
Analysis complete.
The post-meal mystery: is the Hasebe-stamped cracker homemade?
There was one more question: the cracker stamped with the restaurant’s name.
It looks custom enough to raise an absurd possibility: “Are they grilling eel and making crackers in the back at the same time?”
Research found that at least one older review of Hasebe’s main branch identifies the branded cracker as an egg senbei from Asahiken in Osu, Nagoya.
Separate records about Asahiken also show custom senbei made with original branding irons.
Based on the evidence found:
- the cracker uses a Hasebe-specific design;
- at least historically, it was recorded as being made by Asahiken;
- no source was found confirming that Hasebe makes the senbei dough itself in its own kitchen.
However, it could not be confirmed that the current supplier is still the same. Historical evidence and current fact should not be merged.
At least the evidence does not suggest that Hasebe’s eel cooks are secretly required to double as egg-cracker artisans beside the grill.
Conclusion: the general difference is the vessel; at Hasebe, the quantity differed too
Here is what this field investigation established:
- In the general definition, the basic difference between unadon and unaju is the serving vessel.
- Eel quantity and price differences are set by individual restaurants; the names alone do not determine them.
- On Hasebe’s in-store menu during this visit, Unadon Matsu used 2/3 of an eel and Unaju used one eel.
- The unaju therefore contained 1.5× the eel of the Matsu.
- The restaurant was unexpectedly quiet during the visit.
- The oshibori was extremely hot—and an old review records the same phenomenon, weakening the “one-day accident” theory.
- The Hasebe-branded senbei was recorded historically as an Asahiken egg senbei.
- The final food review destroyed all this analysis with one sentence:
It was delicious.
The investigation started with “What’s the difference between unadon and unaju?” and somehow ended with eel portion ratios, oshibori thermodynamics and the senbei supply chain.
One eel restaurant generated far too many research topics.
References (4)
- Japan Ready-Made Meal Association, “Unagi eel rice box”: basic distinction between unadon and unaju
https://www.nsouzai-kyoukai.or.jp/unagi-eel-rice-box/ - Tabelog, Hasebe listing: store scale and currently listed information
https://tabelog.com/aichi/A2305/A230502/23000191/ - Tabelog, older Hasebe review: record of the Asahiken egg senbei with Hasebe branding and the hot oshibori
https://tabelog.com/aichi/A2305/A230502/23000191/dtlrvwlst/B51768201/ - Tabelog, older Asahiken review: example of an original branding iron
https://tabelog.com/aichi/A2301/A230105/23027463/dtlrvwlst/B111767423/
Note: Eel quantities are based on the in-store display observed during the visit. Menu items, prices, suppliers and crowd levels may change over time.
