F is for Fart (2013)

School girl Yoshie is obsessed with her teacher Miss Yumi. One day while outside, a deadly gas breaks forth from the ground and kills anyone who inhales it. Yoshie and Yumi escape into a building where the former wishes to smell the latter's farts instead of the gas. Yumi farts in Yoshie's face and she is transported to a gas-filled dimension where she and Yumi make out. (Iguchi's short movie for The ABCs of Death).