I guess I can't agree with you in the matter of the sequel...Iwaki san is a really matured person and how he always stands up and helps everyone who feels down or ruin is really something amazing. He had a past of hardships that led him to the present him. Its true that he acted childishly overprotective of Katou as he felt jealousy and a sense of competition over him with his own son. But we really shouldn't forget how he helped Yukimaru, Sawa San, Asano kun, and every time Katou, in their time of uncertainty, that shows how truly matured he is. They are humans too, it's only normal that they may run around circles sometimes, isn't that realatable to us? That only shows how much, sensei put her thoughts into making the story with touch of reality. I really look upto sensei and so to Iwaki san for the kind of person he is. For the holes he have, that has been beautifully filled up by Katou. That are truly made for each other to be each others strength in the time of need.
I love this manga. I feel like The sequel has kind of ruined my image of the two of them though. It just seems like they are acting so dramatic and immature in the sequel and just keeps droning ooooon and ooooon. I pretend it didn't happen. I love Nitta Youka so I hope there is a way she can salvage it.
Just look at how much her art-style evolves over the years. It's really amazing. You can see how she changed her art-style throughout the series to keep up with modern drawing styles, but it still distinctly looks like her work.