A doll being kicked around by a puppetmaster is a good anology for people trying to force their ambition onto you without considering what you want to do.

This show is so frustrating with Chiaki not being a good friend to Nodame, for freaking 22 episodes already.

"It's not my business" my ass Chiaki senpai. You're the one who keeps inspiring her to play classical piano even when she doesn't like it.

Chiaki is basically a stick-in-the-mud for the whole season and a bad friend emotionally. TBF, Nodame is childish and can't even clean up her own room or cook to survive, but seems there's some underlying trauma behind all that unfortunately.