"A special cocktail that can only be ordered once a month" is the code used to spend the night with the owner of the bar, Ashihara.

Introduced to this system by a colleague, Murakami had no idea that a simple one-night stand would lead to his becoming utterly obsessed with the cold, arrogant bartender. But Ashihara treats him no differently from any of his other 'customers'…How long can Murakami withstand the torture of being one among many others?