Invaders of the Rokujouma!? - Season 1 Episode 12 Invasion, A-OK!?
Overview: It's December, and they've finally all gotten used to living each other in Apt 106 at Corona House. Koutarou suddenly starts a secret part-time job, even though he's about to start practicing for the second half of the Blue Knight play. The girls all wonder if he got a girlfriend, and start getting jealous. Just what will happen?!