One idea could be that the cat girl maid has special powers that she uses to protect her master from a mysterious threat in the mansion. For example, she can transform into a more powerful feline form at night.
One idea could be a cat girl who discovers she has special powers and has to use them to save her city from an evil villain. Another could be a cat girl falling in love with a human in a world where such relationships are frowned upon.
One idea could be that Cat and Beck get lost in a magical forest during a theater production rehearsal. They encounter strange creatures that force them to rely on each other more than ever, strengthening their bond.
For her personality, make her super curious. She's always exploring the nooks and crannies of the house she works in, not just because it's her job to clean, but because she's genuinely interested in human things. And she has a sassy side, always making witty remarks when the master is being a bit too bossy.
A possible plot is that the cat OC is a magical being from a different dimension. It gets lost in the Naruto universe and Naruto helps it. In return, the cat OC teaches Naruto some unique chakra - control techniques that it has from its own world, which gives Naruto an edge in battles.
One idea could be that Black Cat steals a valuable item, and Spiderman has to track her down. But when he finds her, they discover a bigger threat together and have to team up to stop it.
A great maid dragon fanfic idea could be a time - travel story. The dragon maid goes back in time to the era when dragons ruled the world. She has to find a way to come back to her present time while also dealing with the differences in the dragon society of the past. This could include things like different social hierarchies, magic systems, and cultural norms. She could also meet her ancestors and learn more about her own origin, which would add depth to her character in the fanfic.
Maybe the personal assistant is from a different dimension and has to adapt to the world of Twilight while also using their unique skills to protect her. They could encounter various magical creatures together and the assistant has to learn the magic of this new world quickly to keep Twilight safe.
One idea could be a new student arrives at the Gallagher Academy with a mysterious past and special skills that the other girls don't have. This new character could bring in a new set of challenges and friendships. Another plot could be a mission that goes wrong and the girls have to use their wits and training to get out of a tricky situation. Maybe they get trapped in an enemy's lair and have to find a way to escape while also gathering intelligence.
A 'volleyball girl fanfic' could focus on a transfer student who is a volleyball prodigy. She has to adjust to a new school, new teammates, and new coaching styles. Along the way, she forms deep friendships and rivalries, all while trying to help the team win the championship.
One idea could be that as a girl, Ben has to face different social challenges while still using the Omnitrix to save the day. For example, some might underestimate her because of her gender, but she proves them wrong with her heroic deeds.