Sanda

Both are coming of age action stories with absurd, unpredictable moments, unique cast of characters, and amazing animation. 

These two have the same theme: adolescence. In Bunny Girl Senpai there's the Puberty Syndrome and in Sanda puberty means the end of the stage where you're the most valuable asset of society. 

Transforming main characters who get into violent physical confrontations in a dystopian authoritarian school setting and tend to show a lot of skin whilst doing it. Both shows are somewhat unhinged (though Kill la Kill to a much greater degree) and deal with themes of adolescence, sexuality and independence. 

both anime (rather manga for Litchi) put children on pedestal and deal with dilemma of aging. 

Sanda can be seen as a parody of Mushoku Tensei—in the latter, an adult gets a child's body, and in the former, a child gets the body of an adult. And then both wonder about their situation from the perspective of romantic moves. Some of the lines sound like reverse copies of their predecessors.