One idea could be a story where Mash teams up with an unlikely ally from a rival school. They start off not getting along but through various challenges, they learn to work together and combine their unique skills.
Another option could be a student from a different magic school who is jealous of Mash's popularity and unique abilities. This student could use dark magic to try and bring Mash down.
She might be initially stunned. After all, Percy is a hero and his well - defined muscles could be a sign of his strength and capabilities. It could make her blush a bit, secretly admiring his physical form while also feeling a bit flustered as she tries to maintain her usual composed self.