Hunter lives in a cabin in the woods by himself and has been there for many years. Burdened with severe insomnia, he meets a soft-hearted demon. Since the demon's name is not meant for human ears (for fear of melting into a pool of goo), Hunter decides to call the demon William. Though William is a powerful elder mountain demon, Hunter does not think he is real due to his crippling sleep deprivation, thinking of William as a mere imaginary friend.