Litchi DE Hikari Club

Both are short comedy animations that one might never have thought existed, but exist for the sole purpose of promoting some product. Each comes from a source material belonging to different type of media, but they all share in common mature themes and/or excessive violence. In the case of the adaptations, all the mature themes were thrown away in exchange for a dumb comedy aimed at the original fans, although they are very unlikely to like it. 

Both anime are about a boys' group trying to strenghten their companionship and going after their goal in a rsther brutal way 

What could've been. If you want to see how you fail an anime adaption then watch these two anime. Granted I've never read Pupa but I have heard that the anime mixes up events in the manga making it incomprehensible. In Litchi DE Club's case, they turned one of the best manga ever, which was filled with psychological and horror, into your typical mediocrity comedic shorts anime. It would've been better for the world if these two anime never existed.  

Dark comedy with simple but outrageous animation and pictures, mentoined similar topics like sexuality, aberrations. + using metal/rock music  

They are not identical, however, the jokes and the artstyle are similar at times.