There is at least one scene where penetration happens. It's brief, you still have to progress through the character's stage, and it's not animated, but hey, sex confirmed. The only one I've seen it happen is in Kincha's alternate stage.
Also, just gotta say WOW I did not expect this game to be this addictive. I'm still ass at it but hey, got a couple stages unlocked.
Still not sure how the Steam preview plays like a god, if it isn't a machine...A shame that the scenes aren't animated but the art is good. Bonus points for having guest artists and the guestbook as an idea.