Spoiler (highlight to view)
As the series progresses it is building up on the feelings between Adachi and Shinagawa and there's some additional pinups that hint that the mangaka really intends to have them get together in the end. Also, as the series grows more characters are introduced: Chiba Seiya, Izumi Gaku, Himeji Rinka, Kumagaya Makoto, Akita, ect. So far I've read up to volume 7 (haven't bought 8 yet) and although romantic relationships aren't the main focus, they do play a part in the story.
I *really* loved the part with the focus on Chiba and Makoto in volume 5. When you learn Makoto's identity outside of the game, it'll make you laugh. :>