CAGLIOSTRO NEEDS NERD CR she's done like 239057893490 chemistry projects, probably she's made Koujirou literally run laps around the library grabbing books for her, the poor man.

Also she has health problems/a weak body so he can totally scold her or mom her for overworking herself to coughing up a lung or something. Despite the fact that Cagliostro is half a decade older than him at 21 or something.