Please people, chapter 243 is far too early for any real progress to happen between our romantic leads.
Also, don't forget the school trip arc, which had all this buildup, only for our main characters to go "Hahaha, fuck progress let's preserve the status quo, 'cause we love it!"
This chapter was ... AWESOME. No, not for any reason relating to progress. PURELY for scientific reasons. Also, Fujiso (Gyaru ... at least I THINK that's her name ... can't be bothered to check) is very sexy but she still can't hold a candle to Megumi.