"You may abandon your own body, but you must preserve your honor." - Miyamoto Musashi, A Book of Five Rings

Two weeks ago, in the span of two hours, I ate two black cheeseburgers, one at a Tokyo McDonald's and one at a Tokyo Burger King. The worst part is that it was entirely my fault.

Last month Burger King Japan announced a that it would be selling a "black cheeseburger"—black cheese, black buns, black sauce. It looked disgusting: Shiny rubber on a squid-ink oil spill sandwiched by two charcoal briquettes. I was, coincidentally, going to Japan the next week for my honeymoon. I bragged to my coworkers I would eat one of the nightmare burgers. It was a foolish boast that quickly became a point of honor.

For the first couple of days, I put the hell burger—called the "Kuro Burger," literally "black burger," at Burger King—out of my mind. I ate sushi, ramen, okonomiyaki. It was very good. I liked it.

And then on day three, I was overwhelmed by a combination of jet lag, lots of exploring on foot, and way too many of the delicious little vending-machine coffee drinks you can find on every block in Tokyo (this is an exaggeration, but not by much). The Kuro Burger was growling my name.

At a Burger King in the skyscraper district of Shinjuku, I fumbled my way through the order (I went with the Kuro Diamond—the version with tomatoes, mayo, onions, and lettuce). The cashier accepted my request with what seemed to be a mixture of pity and amusement. Partway through the order, I had second thoughts and added a side salad.

When the burger of slimy black destiny was ready, I carried it to a large upstairs seating area, where I did a quick spin around the packed room to see if anyone else was eating a black cheeseburger. No one was.

You've got to put the Kuro Burger in context: Japanese fast food generally tastes really, really good. In the U.S., it takes a special order to get a real egg on your McGriddles. In Japan, it just comes standard, and it's covered in spicy ketchup. Why would the customer accept anything less?

Burgers are kind of a gray area, though. While high-quality beef isn't a problem, the American version of bacon—still the best burger topping, the shadowy Bacon Lobby aside—isn't readily available. (Later that night, over sushi, an American friend living in Tokyo told me it's the thing she misses most about the U.S.)

The Kuro Burger, though? There are a lot of Japanese innovations that the U.S. should import without delay—vending machines for everything, computerized toilets that cover the sound of your farts, the Caramel Pudding Frappucino—but this is not one of them.

Seeing it in the flesh for the first time was...whelming. Japan has a booming industry dedicated to hyperrealistic plastic meals for restaurant window displays, but that same what-you-see-is-what-you-get ethic didn't apply to the Kuro Burger. It was flat, dull, and limp compared to the staged promotional photos. I would describe the overall effect as "Judge Doom from Who Framed Roger Rabbit? after they melted him with the Dip."

I've seen photos of the Kuro Pearl, the bare-bones version of the burger that omits all the non-black ingredients, and it appears to have even less structural integrity than its deluxe sibling.

That bun, though: It was precisely as advertised. "Kuro" means black, and this thing was kuro as hell. It absorbed all light. There may have been an event horizon hidden somewhere within it. A man could lose a not-insignificant part of his soul in there and not realize it until months later. It was pretty dark, for a hamburger bun.

Unfortunately—maybe fortunately, it's hard to say—the bun's infusion of burnt bamboo didn't affect its flavor in any way I could detect. The charcoal cheese had, if anything, a bit less salt and zest to it than the typical processed cheese slice. The black sauce, a mélange of garlic, shoyu, and squid ink, fared a little better in the tang department, but it was kept firmly in check by the Kuro Diamond's generous (well, large, anyway) slathering of mayo.

The real star of this show, other than the stomach-turning visual of eating black goo, is the patty. It's extremely peppery. It might be more pepper than actual meat. If I hadn't been taking notes, it's probably the only thing I would have remembered about how this sandwich tasted.

"It's exactly like microwave salisbury steak," said my dining companion. She'd hit it dead-on.

Final verdict: It's a burger, but grosser. I did not suffer tragic consequences as a result of consuming it. It did not live up to my internal hype as some kind of Labor of Hercules, nor did it live up to the marketing hype as significantly better or different than any burger you've ever had at Burger King. I probably wouldn't travel 5,000 miles for one again.

And that's where this story should end, but it doesn't. Because our hotel in Shinjuku overlooked a massive four-story McDonald's, it was impossible to ignore the fact that they, too, were promoting a black cheeseburger.

Due to some masochistic sense of duty, I decided I had to compare the two sandwiches head-on. So although I had already filled up on an underwhelming dinner that probably should have been ramen, I immediately headed for round two. Kind of a rip-the-Band-Aid-off thing, except the Band-Aid is made of black squid-ink goop and you have to put it in your mouth.

Luke Plunkett taste-tested the Ikasumi (squid ink) Burger for Gawker sister site Kotaku and, let me tell you, that is a plum assignment compared to reviewing the Kuro. The McDonald's entry is superior in nearly every way, including overall flavor, relative non-grossness of appearance, and the ability of light to escape it.

Its wan greyish-brown bun literally pales in comparison to the Kuro's, but what it lacks in goth cred, the Ikasumi makes up for by tasting a lot like an item of edible food.

"Greyish-brown" is never a good sign in a description of something meant for human consumption, but it's all about what's inside the bun. The burger's guts are a vivid artificial orange, and they're quite tasty.

The main selling points here are a heap of crispy onions, a slice of plastic, yellow American cheese, and a goopy, spicy orange sauce that I honestly believed was another kind of cheese until I Googled it. The combination appears neon-bright between the black sauce and black(ish) bun. Taken together, they do a great job of drawing your eye enough that you can forget you're about to bite into something that looks like roofing tar.

And speaking of the ikasumi sauce, the burger's namesake, that's where I'll have to disagree with Luke. The garlic-shoyu pairing probably affects the overall balance of the burger, but its subtle saltiness just gets manhandled by the bolder ingredients. Its main function is as the only truly black thing about this burger.

The patties are pure McDonald's, flavorless and inoffensive—which is a step up from the Kuro Burger's hockey puck of pepper. Just as in the U.S., these guys are there to add texture and act as a conveyance mechanism for condiments and melted cheese.

Overall, the Ikasumi Burger is a step up from most of the American McDonald's menu—the orange sauce and fried onion bits alone pack more flavor than anything you can order outside of the occasional McRib revival—but it matches up unfavorably with McDonald's Japan's vast selection of breakfast sandwiches. I'd rank it as the second-worst thing I ate in Japan, and that includes a stop at Japanese Denny's.

The Kuro Burger was the worst.

A final scorecard:

Burger King Kuro DiamondMcDonald's Ikasumi
Key IngredientsShiny black cheese, squid ink sauce, meat-flavored slab of pepperFried onions, yellow cheese, neon-orange chipotle sauce
TasteThe worst.The second-worst.
AvailabilityGone, but will likely return next year.Through late October.
Quality of BlacknessThe Dark Knight (2008)Batman: The Movie (1966)
PriceJust slightly less than the ramen you should eat instead.About one-third bowl of ramen.