It rarely snows but it does get cold in Tokyo during the darker months of winter. But not ridiculously, "Scott of the Antarctic", so; and it tends to be a "dry" experience rather than the "wet" bone chilling cold of my home country that saps your very soul no matter the insulation you wrap yourself within. Indeed, an hour outside the capital in the mountains of central Japan, the temperature just before dawn will often fall to -15C however the air is so dry you can drink your coffee in a t-shirt outside happily chatting to a neighbour.
And whilst the macaques are rolling snowballs in preparation for a pre-emptive strike, strangely the neighbour will be hanging out their washing to dry in this sub-zero world of ice and snow. Taking advantage of the low humidity and lower temperatures, the villagers of central Japan have figured out that sublimation does actually work where ice changes spontaneously to vapour without melting first (look it up if you've forgotten your high school physics...). The result being your socks will dry a treat despite the weather giving Hell a good run for its money. And then there's the ice age.
Japan is, give or take a Roman Empire or two, approximately on a par with the latitude of the northern coast of Africa and so the polar ice sheets never actually made it all the way to Tokyo some 24,500 years ago as they engulfed North America and the western reaches of Europe. But the heights of the Northern and Southern Alps (as the central mountain ranges of the country are known) were sufficient to generate their own glacial flows and so classically smooth sided super-valleys and areas terminal moraine can be found when you know where to look. And soon it'll be summer. 40C and 100% humidity, and we'll all be wishing for winter's sweet chilling bite once again.