I have read all the current reviews, and they all have good points! Some do say that its ecchi, lewd, perverted. However, in comparison to "ecchi animes" that i have seen so far, this falls on the light side. Yes, they do show female underwear and sexual innuendos, but thats all there is to it.
(From here on: May contain spoilers!!!) You may notice that the storyline starts getting weird