I think chapter 12 actually qualifies as character development for Tanaka - he was proactive, not just resisting Ueno, but working around her demands.
Of course, Ueno and Yamashita weren't as pleased to see that development as I was...
On another note, I just want to explicitly thank Bainhardt for doing this. This is pretty much my current favorite manga, and it's only in part because I enjoy the manga itself. It's not just that I know when I see a new update that I'll likely laugh out loud at it, but that I know I'll be experiencing careful, quality work from a conscientious scanlator.