I have been blindsided by PLOT so many times. ^^;; One of my favorites, Kiddy Grade, goes from fanservice-y action comedy to a freight-train of PLOT right in the face with almost no warning.

I definitely have to be in the mood for it, and it's one of the main reasons I prefer binge-watching over weekly-as-it-airs, because once the plot/drama hits, I end up chewing my fingers off while waiting for the next episode.