It's quite a surprise to see a working chocolate factory in an airport, and Chitose Airport in Sapporo, Hokkaido, Japan, has one: the Royce' Chocolate World. You can view the process from finish to end along the stretch of the terminal. They have recently renovated the terminal and it looks like a small amusement park. Aside from the chocolate factory, they even have a Doraemon Park.
Royce' was founded in Sapporo and they're known for making very good quality chocolates. I first encountered Royce during a visit to Hong Kong, and I've always managed to bring some home. They're popular in Asia. But since then, branches have also opened up back home in the Philippines. In fact, they have also very recently opened their 1st US store in New York and a second shop in Russia.
My favorite is still their Classic Bitter Nama Chocolate made with dark chocolate. Each box comes with a small spatula used to lift each piece of chocolate from it's casing. The chocolate pieces are also sprinkled with powdered chocolate on top. Aside from the usual milk chocolate and white chocolate flavors, they also have Maccha or Green Tea flavor. Their Nama chocolates are also available in chocolate liquor versions.
Some other unique items included their chocolate covered potato chips or some with strawberry or lemon fillings.