As far as I've read, I think Aka still belongs entirely to Matsumaru, though she's sometimes living with the manager to keep people from finding out about her relationship.
I like this manga, but sometimes it seems to be getting pretty redundant. It seems like half the story is an endless repetition: Matsumaru and Red get a moment alone, try to ****, something happens to prevent them having their second time.
I sort of wonder if anyone's going to try to animate some of Q-taro's other works. I'll admit it seems sort of unlikely. REC's just about as clean as I've seen in his stuff. The other major work I know of is Momoiro Sango, which focuses alot on the main character's renters(three sisters) finding new and creative ways to torture him with sexual frustration. I'm wondering, do any of this guy's works either have little to no sexual content or at least not involve constantly unfulfilled desire?