Sarah and Kat are having a slumber party and their parents tell them they have to invite Kisa, the most unpopular girl in school. So, they cope with the situation by being very very mean to her when she arrives. They hide her phone, make fun of her, and even scare her. Kisa has plans for her own revenge on these two mean girls and it involves two very sore, red bottoms.

Sarah and Kat are having a slumber party and their parents tell them they have to invite Kisa, the most unpopular girl in school. So, they cope with the situation by being very very mean to her when she arrives. They hide her phone, make fun of her, and even scare her. Kisa has plans for her own revenge on these two mean girls and it involves two very sore, red bottoms.