Park Hwa-young lives alone at home where her so-called "friends" freely use to hang out, get drunk, and have sex. While they call her "mama", they never let her join their clique except for Mi-jeong, the clique's queen thanks to her relationship with Young-je, a high school hooligan. As Young-je disapproves of Mi-jeong to hang out with Hwa-young, Hwa-young can only await her at home.