From the introduction:
The summer of Nihon is long, and dry, and hot. Your lady love has asked you to bring her snow from Korea to cool her brow. Can you bring it back before it's too late? Will the dragons of the ocean stop you before you return? Will you survive the armies of Korea and the hengeyokai of your own province's outlands?
The characters in Snow From Korea are samurai men, the devoted lovers of samurai mistresses home in Nihon. They have been sent to Korea (or any of the other barbarian countries of the Sunset Kingdoms) to recover some rare and precious thing, which the samurai call the Snow, from a line in the popular story The Tale of the Heike where one of the court ladies says to her lover, "The summer is hot. Bring me snow from Korea to cool my brow."