One January I visited Hakodate and my, was it ever snowy! The whole town was covered, and while not as deep as at Lake Onuma, there was still a special atmosphere, calm but still festive.
I took in the view from the top of Mount Hakodate, popping outside for a few seconds to take pictures, then going quickly back into the warmth. It was fun to wander slowly round the town - it had to be slow, really, as it was either crunchy snow or slippery ice underfoot - breathing in the fresh winter air, then watching the mist as I exhaled.
Then when I came to leave, my flight was delayed for three hours by a snowstorm.