Evil Recruit 2 ~Heroes Are Nothing Against My Farts~

Sakura and Aoi were women with farts so smelly they had a hard time fitting in anywhere... Until they joined Asterism, a secret society. They fought off their enemies with their farts and managed to rejoin society gracefully.

It's been 3 months since then. And a speedy promotion awaits them. But their troubles haven't ended. Now they'll have to face the rage of their coworkers, going on strike for what they believe is an unfit promotion; their superiors, challenging them to a duel, and a new organization of heroes, Clean Force, who they'll have to face.

[From DLSite English]