Following earthquakes in Kumamoto Prefecture, Natsuna Keyaki loses contact with her online friend Itsuki. Armed only with a sketched landscape, she sets off from Tokyo to Kumamoto in search of him. Amidst the post-disaster confusion, Natsuna finds herself lost until she crosses paths with a policeman and lively middle schooler Izumi Chiba. Welcomed by Izumi and her family, Natsuna receives aid and a safe haven. Guided by these newfound companions, Natsuna edges nearer to unraveling the mystery surrounding Itsuki's disappearance.