Natsume is at home early one evening when he hears a knock on the door.  He sees Tohko outside, asking to be let in.  But when he opens the door, there's nobody there, and a gust of wind rushes past.  Another Youkai is after the book of friends!
and then, when the sun set,
 she would finally head back down.
Como se marchaba cuando 
empezaba a caer la tarde,
Como él se iba cuando empezaba a atardecer,
e só voltava para casa quando o sol se punha.