Certain people, at some point in their life, dream of a Key, and if they so choose, grab it, opening a world outside this reality, unique to themselves. Those who decide to share them with the world are known as Keyholders. Oliver has had his key since he was 3, and has been developing his world ever since. Now 14, he finally builds up the courage to become a Keyholder, though anonymously. Inspired by his idol and his friends, he sets out to fight Nightmares.