Suzumiya Haruhi no Yuuutsu, Seishun Buta Yarou wa Bunny Girl Senpai no Yume wo Minai Recommendations
Both series contain:
-supernatural themes with philosophical notes
-annoying clingy imouto to MC
-male MC who is somewhat dull in contrast to the main female character who is popular in school
-high school mystery/drama
-mysteries that are supernatural in nature
Overall both series are really interesting/unique from most series and both worth checking out imo.
Both main characters are mellow narrators.
Both main girls are odd.
Both have supernatural elements in the premise.
-Both series have a sarcastic main character
-Both of them have an odd main girl
-Both of this two series are mainly set in a school, but have supernatural elements
-we follow diferent arc-like stories
Apart from the bunny girl outfit, both anime also share the concept of time loop.
The two have similar the what i call "Supernatural cherry on top", different mysteries every episode and the MC has to solve it.
Plus both have Bunny Girls! How awesome is that?