Mom and the family are going north in a rental car.  They take a break to play in the snow, but suddenly catch sight of the figure of a furry animal.  Next to them is a "Watch out for Bears" sign. They panic and return to the car, but it's not starting and won't move...; Mom and the family are at the home of the owner of the St. Bernard, Mr. Furusawa.  Dad says that every house in Hokkaido is guaranteed to have a bear in it...; Mom and the gang have gone skiing.  Bunji gets really good in a short time, but he gets over confident, goes off on his own, and falls off a cliff, getting separated from everyone; As they approach the end of an enjoyable trip, they arrive at Cape Soya. If you weigh yourself there, you will find you weigh far more than in Tokyo.
Oh dear, that must be it.