At her friend’s birthday party, Ane comes wearing gas mask. She is the only one to escape from the party when all the other guests suddenly pass out. Although the gas mask protects her from the polluted air outside, it can also be an obstacle for these mature and independent girls, who believe they are already ‘perfect beings’. Proof comes in the final scene when all the girls freely breathe fresh air by a big lake after negotiating dark and narrow underground passages. (HWANG Hye-min)