It wasn't trying to suck you into the story at all, It was just something for someone looking at the characters as objects. I for one like plot with my Ecchi-manga, and nice plot at that.
Rinko is best and yet it was a shallow attempt at an Ero-manga, same with Nene, no soul. 6! You can't just put characters in with no plot, it's like a Magician without magic.