The worlds can be divided into two—ones of spirit energy and others of matter. Only certain types of beings can cross the bounds that separate those different worlds: human masters and demons. Both Jaechul and Moonsoo can cross those bounds, and fate has them become unlikely companions on a long and possibly deadly journey. With objectives and personalities that are far from similar, will the two (along with the dotgabi Nap) be able to complete their journey and return to the lives that they hold dear? A new wind is starting to blow, a wind that carries the wishes of many.