They were all top Atlas Academy graduates, who could’ve signed up for the military, but Robyn and the Huntresses chose to stay in Mantle. She’s gunning for a seat on the Kingdom’s council, and when she gets it, she’s gonna put an end to Ironwood’s tyranny!
In "A Night Off", the Happy Huntresses serve as security personnel for Robyn in her election celebration party, failing to identify Tyrian Callows as a threat. After Fiona is injured by Tyrian's attack and Jacques Schnee is elected, Robyn and the Huntresses become full-on vigilantes for Mantle's sake, stealing military equipment to fix Mantle's wall.
They participate in Mantle's defense during the Battle of Mantle. They appear to work together with Ruby's Group and Ironwood's Group to stop the Grimm invasion and defeat and arrest Tyrian. After Ironwood stops the evacuations in mantle and declares martial law, the Happy Huntresses have a falling out with Ironwood's Group when Robyn attempts to fight Clover in the airship carrying Tyrian and In the ensuing fight accidentally free's him. Tyrian crashes the ship and Robyn ends up getting injured in the process and Tyrian kills clover. When Atlas Soldiers later come to arrest Robyn and Qrow, they are both sent to prison after being framed by Tyrian.