The way you carry yourself is important when displaying reasoning. I don’t think this attitude will get you very far or get many to agree with you.
First, I wouldn’t even say Mitsuri is sexualized (crazy statement, I know). The two fanservice moments happen during season three episode one , and that’s about it. Besides that, she’s not really sexualized. To say she is would be saying that a girl’s body is inherently sexual, which isn’t a very good thing to be saying. I’m not saying that her design wasn’t influenced by those ideas, but overall, I find it hard to say that she’s a fanservice character.
Mitsuri is her own character with her own wonderful story to tell. Not enjoying it is fine, but to act as if it doesn’t exist or is somehow “lesser” than other characters’ stories is certainly an opinion I’ve seen. Her story is meant to be more down to earth, displaying the themes of finding a place you belong, finding love, and living in a world that seems to reject you. Those ideas presented in her story are part of the bigger themes of the story, like the value of human connection and self-acceptance.
Her story also relies on the time period she’s in and the role women were meant to fulfill during that time period. Initially, her special traits were something she was proud of. But after realizing that men didn’t like her because of what made her special, she tried to hide those traits away and just be a normal girl. She soon comes to the realization that wouldn’t bring her happiness either. So she embraces her femininity and the things that make her special since they don’t make her less feminine or less of a person. She embraces who she is and still does what society expects from her, but in her own way and by her own terms.
It’s heartfelt and sad, but it ultimately displays that love can be found anywhere and to not let yourself be dragged down by societal expectations if you don’t fit in. I enjoy how uplifting it is.
That’s as far as I’ll go to avoid manga spoilers. Besides, I think I got my point across. There’s a lot more to Mitsuri than just her body. I’m sorry you couldn’t look past that.