My most hated female character.
I hate that, that character eventually married the (significantly more valuable) protagonist. I lost interest in the Anime long before that, but it definitely contributed to my loss of interest.
The character does nothing but hit and scream for a long time. THAT IS NOT ATTRACTIVE. IT WAS NOT EVEN SEXUAL WHEN IT WAS DONE (I don't care if there was a "hint" of "romance and care" for the early compulsive hits and screams, and maybe it became sexual by the end but I don't know because I haven't finished it so far (traveling by an airplane to some portal was a good enough point for me to stop watching at)).

I thought Shana was worse.