After yet another one of Fairy Tail's adventures causes collateral damage, Makarov ordered Lucy and Erza to find a part-time job to help pay. Coincidentally, a wealthy retired sorceress had opened up a water park nearby, which had it's own aquarium with a mermaid exhibit. Not being able to resist both he money and the free publicity as a PR stunt, Makarov sent them there to be hired as mermaids.