Have u seen atau do u know of any series where the male character has an older sister who is protective atau even overly protective of him?

Seiji Yagiri has an older sister, Namie that somewhat fits that description.

MM! Taro's older sister is very doting and overprotective, claiming to care about him lebih than their mother does. (Of course, they're both overly caring, and he's pretty sick of it.)