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!
but I don't want you getting sick again,
No quiero que se ponga mal. 
Ya debería marcharse.
Pero no quiero que esto afecte a tu salud, deberías irte.