Apartments and such!

So, I'm a big fan of a manga called 'Hot Gimmick'. For those unfamiliar with it, here's the wikipedia link:

http://en.wikipedia.org/wiki/Hot_Gimmick

Basically, I'm looking for books that have to do with relationships inside of an apartment building/complex. I hope that's not too vague? Thanks in advance!

Edit: I'm not sure if I made it too clear, but it doesn't have to be other manga. It can also be books. :P