MOSDO was launched in 2008, a joint effort between MOS Burger and Mister Donut. While at first the tie-up just meant a certain amount of menu overlap between the two chains, the collaboration gradually led to a handful of dedicated MOSDO shops—and some pretty crazy doughnut-burger hybrids.

In 2014, MOSDO introduced our two favorite items: the Curly Chorizo—a spicy chorizo sausage, MOS chili sauce, lettuce and tomato on a French cruller—and also the Berry Chocolate, a French cruller topped with a crispy chocolate disc, mixed berries, strawberry whipped cream and mango sauce. While we can only hope these ridiculously indulgent doughnut-burgers will come back someday, meanwhile you can check out MOSDO below to see what's hot and new!

America may be the home of McDonald's, but Japan is where its hamburgers go to spread their wings and take off into flights of fancy. In 2010, McDonald's Japan released Big America, an American-themed burger series showcasing burgers inspired by Texas, New York, California and Hawaii.

The campaign did so well that McDonald's launched Big America 2 in 2011, which included the Texas 2, Idaho, Miami and Manhattan burgers. In 2012, the third round introduced us to Las Vegas, Grand Canyon, Broadway and Beverly Hills-inspired burgers. Will there be a Round 4?

During the winter holidays of 2011, Burger King Japan announced the NY Pizza Burger—an enormous, family-size burger measuring 22 centimeters (8.8 in) in diameter! Available on its own or as part of the Christmas BK Party Set, the set added BK Chicken Tenders, BK Cheese Bits, onion rings and a salad.

There were even two versions of the big burger: Fresh Avocado and Nacho Cheese, though you could only get either of these options on one side of burger, while the other side would contain the standard Whopper toppings.

In March of 2012, Burger King Japan released the BK Ringo—a burger with lettuce, honey mustard, mayo and a slice of apple (ringo in Japanese). The dominant flavors were the sweetness of the apple and honey-mustard, with an overall taste somewhat similar to an apple pie. It didn't look pretty, but the combination of apple and beef was oddly comforting.

Released by Lotteria, the Zeppin Cheeseburger (or "Superb Cheeseburger" in English) presented five tiers of patties with cheese, while the Ebi (shrimp) Tree Burger was composed of five stacked fried shrimp cakes. If the ¥1,360 and ¥700 (respectively) price tags were too steep, the Zeppin Cheeseburger was offered at a reduced rate of ¥500 on "Cheeseday" (Tuesday, a play on the Japanese pronunciation of the day), while the Ebi Tree Burger was ¥500 on "Fryday" (a play on the fried shrimp in the sandwich).

MOS Burger released the Sabamiso Rice Burger in the autumn of 2013. It might look like a very new concept for those living overseas, but it's actually quite a simple recipe, as it's just a typical Japanese lunch combination: mackerel cooked in miso with strips of leek as a topping. The only twist was sticking it between compressed rice cakes. It wasn't your typical burger, but it was safe to say it made for a healthy choice!

In September of 2013, a home-delivery pizza chain in Kyoto, Pizza Little Party, offered a unique twist to its pizza with the Mega Burger Pizza—a burger-like pizza measuring 27 centimeters (10.6 in) in diameter and weighing in at 1.2 kilograms (2.6 lbs)! The Mega Burger Pizza was offered for only three months, but apparently did well enough to be brought back in November 2014, this time including the Mega Bacon Lettuce Burger, the Mega Teriyaki Burger and the Mega Teriyaki Chicken Burger. Perhaps we can hope for a further expansion in the future?

Japan is known for its succulent wagyu beef, but most people familiar with the meat probably wouldn’t expect it to be served as… a hamburger! But in 2014, that’s exactly what Japanese fast food chain Lotteria did—serving a different kind of wagyu hamburger each month as a campaign over the period of about a year. One of the most striking burgers was the Tochigi Wagyu Hamburg Steak Burger, which came seasoned with Tochiotome strawberry sauce.

MOS Burger has built a reputation over the years for its healthy burger options. For those with an aversion to traditional wheat-based buns, MOS Burger offers versions made with grilled rice patties—and if you’re counting calories, they’ll simply wrap your filling in lettuce.

In the summer of 2015, there was an even more impressive option for health-conscious customers: a burger stuffed between two halves of a giant tomato. It was available after 2 p.m. from the MOS Burger branch at the Think Park Plaza store in Osaki, Shinagawa-ku, Tokyo—the only one to sell it in Japan!