From here:
Mitsu is in love with Madoka, who doesn't even know she exists. Mitsu's pretty happy stalking Madoka, but is a little careless about it and, one day, she's hit by a truck and killed. But now she can REALLY stalk Madoka - and drive away all the boys - and girls - that show any special interest in her. Woo-hoo! Plus she gets to be there when Madoka changes clothes and…