Yatsusaka Naoya has had since little the ability to see invisible things, for which he got alienated from his classmates. In the present, he lives with the family head representative, Isuzu Satsuki, and since the gruesome death of her parents, Kuroba Nao.
He dreams with a girl, and gradually remembers he used to meet her in the forest when child. And when he goes to the fireworks festival with Nao, he'll take a decision that will change his destiny.

Akashi no Kuni includes Nao's route.