If you check the last chapter, on the back of the manga it says that the characters were based on Venom, Darling Dance and Failure Girl , and they look exactly like the characters from the covers of the songs (expect Ruru, who look like the character from the cover of the Venomer album) there's...
Honestly I think this adaptation is rll good. Also I think the main character "Lulu Chugaku" is not based only on the song Venom but also from the whole album Venomer, but I could be wrong, since Venomer is an album that only features remixes