The first Mos Burger opened in 1972 in Tokyo. The first franchise shop appeared in 1973. By 1979, Mos Burger opened its 100th restaurant. Today there are 1,361 shops in Japan, 148 in Taiwan, 23 in Singapore, 9 in Hong Kong, 7 in Thailand, and 1 in Indonesia.

Satoshi Sakurada, the founder of Mos Burger who passed away in 1997, named his burger shop Mos, referring to mountains, ocean, and sun.
Satoshi Sakurada, the founder of Mos Burger who passed away in 1997, named his burger shop Mos, referring to mountains, ocean, and sun. Mos Burger is known for using fresh vegetables and uniquely Japanese sauces and flavors in its meals.

Eating at Mos Burger can be a unique experience, but this fast food is not necessarily fast. Most Mos Burgers prepare the food only after it's been ordered, and customers may wait 10 to 15 minutes for their orders to be ready. 

In addition to offering standard type hamburgers and cheeseburgers on the menu, Mos Burger also offers burgers that can't be found at McDonald's or other shops in Japan. One of these burgers is called the Rice Burger which replaces the bun found in typical burgers with two flat round patties made mostly of rice with barley and millet. The Rice Burgers may be hard to hold with bare hands, however most people in Japan tend to hold burgers and other sandwiches using the wrapper anyway.Other unique offerings include the "kinpira" rice burger. Kinpira is a dish made with root vegetables such as lotus, carrots, and burdock that are sautéed with soy sauce and other flavorings. The "Ros Katsu" burger is made with "Tonkatsu" a Japanese food made with deep fried pork cutlet served with a sweet barbecue type sauce and cabbage on the side. The Ros Katsu Burger is a deep fried pork cutlet topped with shredded cabbage and tonkatsu sauce. A new burger that was introduced recently is the "Donut Burger" which features a round hamburger patty with a hole in the middle. The patty is served on bread with lettuce or with lettuce and tomato. It is topped with a wasabi-mayonnaise sauce.

The Mos Burger menu is not limited to burger and sandwich type items. Mos Burger offers plain hot dogs, chili dogs, and spicy chili dogs which include sliced jalapeno peppers on top of the chili topping. There are also chicken nuggets and fried chicken on the menu. Side menus include salads, french fries, onion rings, and french fry-onion ring combination sets. Rice bowl meals, soups, and other special items may also be offered and vary by season and area.

Mos Burger desserts include frozen cake bars, milkshakes, and parfait type desserts, all made with Japanese style ingredients. The drink items offered include Pepsi, Iced Coffee, Iced Tea, Orange Juice, Melon Soda, White Grape Soda, Oolong Tea, Iced Café Latte, Iced Cocoa, as well as hot tea and coffee.

Kid’s menus at Mos Burger offer a kid sized hamburger or rice burger, a side order of french fries, and a box juice.

Mos Burgers can often be found as a part of food courts in major department stores, but there are also many stand-alone restaurants. It is the second largest fast food chain in Japan after McDonald’s.

There are also four restaurants designed in collaboration with Dick Bruna featuring his characters in the shop. The first shop and prototype is in Tokyo’s Kunitachi City. The second is in Kanagawa Prefecture called the Ocean Cafe Enoshima Shop. The third Dick Bruna Mos Burger shop is also in Tokyo, this one in the world famous Ginza District. There is also a shop with the Dick Bruna theme in the Think Park Plaza in Tokyo.