There is plenty of rain along the Pacific coast in summer in Japan, but winter is the reason for the snow along the coast of Japan?
In summer, influenced by the summer monsoon, the southeast coast of Japan is rich in water vapor, and the terrain rises more than the terrain precipitation, so the southeast coast is rich in summer rainfall. In winter, due to the influence of the northwest monsoon, a lot of water vapor comes out of the Sea of Japan, and there are many snowstorms due to the severe cold weather and the rising terrain! I wonder if you are satisfied with this answer?