I wonder how long he can keep going from happiness to depression and back again before killing himself. That's probably what the girl is wondering too I guess.
It's cute how thirsty Ueno is and, at the same time, how easily Tanaka can please her. Cute and kind of sad really, I hope they get together by the end of the manga.
Just found out 18 and 18.5 were posted on /a/ more than a month ago yet nobody uploaded them here. For shame guys, for shame.
Also a big thank you to the good lads translating this.