Quote from Crenshinibon

You could make a case for The Melancholy of Haruhi Suzumiya, although I'm not totally sure if she qualifies as a tsundere or just a person with a really flamboyant personality.

or just god.

midori no hibi the side character ayase fite the supreme definition of tsundere. plus she gets alot of screen time

w-pinch♥ 🤨 🤨

Onidere, also Working!! may apply, but I don't think it has been determined which character will be the romantic interest of the protagonist. But there is definitely a tsundere character that is one of the characters likely to be the romantic lead. She seems to get along with the protag until she remembers he's a guy and her androphobia kicks in and she beats him up.

Has anyone mentioned B Gata H Kei yet?