Iris Calvafon, a 16-year-old girl.

The bookstore girl who was divinely chosen, and possessed a magical grimoire.

But the truth is, she's just a normal girl who loves books, especially adventure novels.

The elven swordswoman, Tosrillon. The werewolf thief, Carotayle. The warrior priestess, Rosalith. After meeting these three people, Iris' realizes that she strongly yearns to go on a real adventure of her own.

Iris decided to join them, despite the danger.

And with that, she set off on a wondrous adventure alongside those three girls. It's that kind of story.

A story where the ordinary girl shall use a mysteriously powerful grimoire, and become a hero.