The crab croquette contains diced red snow crab and mushrooms, in a Sauce Américaine, which is made of pounded lobster meat and shells. The croquette is topped with lettuce and a hearty tomato sauce and served on a ciabatta bun.
The price tag on the burger is 390 yen (~$3.24 US) and it's available through early January.
Croquettes are pretty popular in Japan but are more often stuffed with mashed potatoes rather than crab.