Jeez, I just finished with MK2 and Bankunyuu, and now I gotta grab two more. Not that I'm complaining, but sounds like a busy night.
Bakunyuu: It's alright, seems like there should've been more action though. Also my favorite girl got barely any action, and despite there being multiple guys there wasn't really any gang bang. Disappointing.
MK2: Not sure if I like the first one better or not, but this was certainly awesome. I don't quite understand the whole Ninja thing, but it lead to a gang bang so - hooray! Might be my pick of the month. We'll have to see...
Edit:
Karutagura: This one was really boring from what I saw skipping through it. Pretty vanilla sex, bland character designs, and perhaps too much story that I can't understand. Maybe I'm being too harsh on it though.
RB3: Too many chicks on the dance floor. Seriously though, I love Mika but her scene did little for me since it was a yuri scene turned into a three-some with two girls. Then the scene at the end with three different girls on the same guy. The one-on-one scenes are pretty great though.