Joyfull calls it “Water Surface Slash” beef. The photo shows thin slices of meat.
So where’s the water?
The official page cited by the original article on September 8, 2026, priced Joyfull’s Demon Slayer dish “Tanjiro’s Flame Dance Hamburger & Giyu’s Water Surface Slash Beef Yakiniku” at ¥1,199 before tax and ¥1,318 including tax. It described cheddar, garlic sauce and shredded chili as Tanjiro’s flames, and thin-sliced grilled beef as a reminder of Giyu’s Water Surface Slash.[1]
The fire has ingredients assigned to it. The water has thin beef.
Water Surface Slash, but where exactly is the water?
Photo taken from an in-store menu. Tanjiro’s side visually reads as flame through red/orange sauce, cheese, and shredded chili. Giyu’s “Water Surface Slash” side is mainly thin-sliced beef; no obvious blue or liquid-based water effect stands out in the photograph.
Joyfull does not say that a blue sauce literally represents water. The official copy simply says the thin-sliced beef is intended to evoke Giyu’s technique.[1]
So “there is no water” is not an accusation that the product contradicts a promise. It is a reaction to the distance between the technique name and the visual design.
Tanjiro’s half makes the flame’s color and movement easy to see. Giyu’s half depends much more heavily on the name of the technique. One can joke that “thin slices = something got slashed,” but that is our interpretation, not Joyfull’s official explanation.
In short: the flame is visible; the water mostly lives in the name.
Does that mean Joyfull collaborations are really “name only”?
No. Past Joyfull product-development reporting gives clear counterexamples.
In Gourmet Watch’s 2024 report on the Joyfull x PEANUTS campaign, a product-development representative said the team visited Snoopy cafés and shops, researched what fans liked, developed more than 20 menu candidates, and narrowed them to 10. Even dishes that appeared to use ordinary Joyfull ingredients included collaboration-specific changes such as thicker bacon, different sausages and potatoes, and special ingredients.[2]
In 2025, a PEANUTS version of Joyfull’s regular summer youlinji-chicken udon was also described as a special collaboration presentation with more colorful plating.[3]
So the reality is neither “every dish is built from zero” nor “they only changed the name.” A familiar base can carry special changes in thickness, ingredients, sauce, presentation, character decorations, names, and campaign goods.
Ordinary-looking food can still have special changes
Next to a themed café pancake with a character’s face on it, this beef looks like an ordinary meal. But starting with familiar food and changing the meat’s thickness, sauce or presentation is another way to make a character menu.
Using the kitchens and ingredients a nationwide chain already has sounds easier to me. That is my guess, though, not Joyfull saying it chose this approach to cut costs.
Ordinary-looking food does not necessarily mean ordinary development. The Snoopy team worked through more than 20 ideas, selected 10 and even changed the bacon’s thickness. A photo does not show all that work.
And doing the work does not guarantee that a named technique will be obvious in the photo. Giyu’s water still seems to need help from the name.
Looking for the water produced an article
I did not set out to investigate menu development. First came “Where’s the water?” The official explanation led to thin beef. That raised “So is it just a name?”, which led to the older development reports.
Once, I would have posted “Water Surface Slash—where’s the water?” on X and stopped there. Now I ask AI about the question, look at the explanations and ask the next question. The conversation becomes material for an article. I have not suddenly fallen in love with blogging; my usual muttering has just got longer.
Tell me to write 2 articles every day and I would quit on day 0. Let me eat out and ask “What’s this?”, and the things I find out stay behind. A writing quota and following a question feel very different to me.
Answer one question and another appears beside it. This time, invisible water in a beef dish led all the way to changing the thickness of bacon.
To put it crudely: eat a question, digest the information, poop out an article. Articles are the poop of intellectual curiosity.
The water never turned up.
The article did. This time, with a photo.
References (3)
- Joyfull: Demon Slayer menu joyfull.co.jp
- Gourmet Watch: development of the 2024 PEANUTS menu gourmet.watch.impress.co.jp
- Gourmet Watch: special 2025 PEANUTS menu gourmet.watch.impress.co.jp
