The first time it is mentioned, Michiko tells Satsuki it's time for school, and they must go. The second time is when Granny and Mei turn up. Mei refuses to be without Satsuki and won't stop crying, so Satsuki has to have Mei sit in on the lessons with her. The lesson continues with Mei sat between Satsuki and Michiko. Mei draws Totoro while she is there.