In “Moon Girl’s Day Off”, the stress of being a superhero, meeting with people, and excelling in school starts to take a toll on Lunella, physically and mentally. When Casey adds a photo shoot to her schedule, Lunella fakes a twisted ankle, so she can rest. She has Casey wear a modified version of her Moon Girl suit, so she can go in her place.
While Casey struggles with the attention and hard work Moon Girl deals with, Abyss — a reluctant fifth-generation super villain Lunella fought earlier in the episode — returns to exact some revenge. Devil, knowing that Lunella lied about spraining her ankle, calls Lunella to tell her what’s going on. As much as she wants to help, Casey isn’t ready to take on a villain on her own.
Lunella is talking to her grandmother Mimi when she gets the call. Her grandmother wisely figures out she’s faking it. They have a heart-to-heart about how important it is to be honest with the people who love you. They cannot properly support you unless they know what you need. Lunella asks Mimi to give her a ride to help Casey with a “project”. They hop on Mimi’s motor scooter, and we find out that Mimi is an awesome driver.
While trying to help Casey, Lunella experiences karma and twists her ankle for real. Together, the duo is able to freeze Abyss in a block of ice. Lunella admits that she lied, and Casey is quick to forgive her. Casey finally understands how busy Lunella is, and lets her rest. Abyss escapes, but calls her mother to tell her she’s done with the villain life and is switching careers.