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!
Sorry, I lost my key.
Disculpa.
Perdóname.
Desculpe, esqueci a chave.