Ao no Flag was one of the most immersive and ground breaking manga I've ever read, with amazing art and deep characters, and extremely deep relationships. It was well on its way to a 9 or 10 rating (rare for me) until literally the final 2 chapters. I'm not going to spoil here, but essentially the whole story and pace of the narrative is flipped on its head for some kind of political statement. Again, I agree with messaging being pushed, but to really lead reader on for years, and then to shove this horseshit in our faces at the last minute, is just inexcusable.
If you are going to read this, and don't want to feel a severe sense of disappointment, confusion, and then anger, do yourself a favour and stop at chapter 52 and leave the rest to your imagination.
