Everything boils down to how petty the whole Hana x Kiyoshi revolved in the end, Mainly due to Kiyoshi being a dense wuss and not stopping the train on its track. Also, it was shocking in that how Chiho did a 180 and ended like Mari and how Mari was so done that she went away. Bonus points for how pointlessly long was the calvary arc and how it (the manga) never delivered (kinda) on the wet t-shirt contest, which was for most of us, the end game.
I stand on the opinion that once they got out the jail it was a done deal story, but I guess he/they had to milk it?.