I don't know whether there is a specific japanese cultural explanation, but in general it often was. In winter when it was cold, those who lacked the strength to go on, layed down in the snow to rest forever.

Everything dies in winter. And then is reborn. Everyone who lives in a cold climate knows deep in their bones that cold and winter are death.

Though if we're going to get stereotypical about national characteristics (a dangerous game) then what might be more specifically Japanese is the particularly heightened understanding of this cycle. Or at least, its expression in art, when in the west we might flinch away.

I'm currently reading Sea of Fertility so probably some of Yukio Mishima is drifting into my thoughts here. (Explaining puns ruins them but there it is again: Yuki o. Snow.)

I don't remember who said it, but a statement that has stuck with me is:

The moment when the most you can do is less than the least you need to do, you die.