The 50 Series 51-Type Passenger Car debuted in 1979 as a general-purpose passenger car for Hokkaido. Based on the 50 Series passenger cars for Honshu, it features cold and snow-resistant equipment such as double windows and axle generators, allowing it to excel in Hokkaido’s major lines. It retired in 1994, before the warm-region versions, but remains a key train when discussing passenger trains in Hokkaido.