Karuizawa has long been known as a retreat for wealthy families fleeing Tokyo’s summer heat. It’s where, in 1957, the Emperor Akihito and Empress Michiko famously met playing tennis.

At the foot of Mt. Asama, lies Karuizawa, one of Japan's most well-known resort areas. In the late 1880s, foreign missionaries began building holiday cottages in the town to escape Japan's fierce ...