
I can definitely understand how you feel, but I think you're looking at this from the wrong lenses. If Iwaki starts to treat Shou as a son, it would complicate more things than how he's treating him right now. First off, it would be extremely weird for Iwaki to treat a stranger like family when he never knew he even had a son. He cares about him deeply, as you can see from him and Kato's conversations and how he wants Kato to keep tabs on him, but it's better for everyone if he cares from afar. Second, the media would eat Iwaki alive if they found out that he had a son, and that can also destroy Shou's acting career, because people would suspect that he got all of his acting gigs from his father's influence, and that's not the case. Also, even though Shou wants Iwaki's care, he also wants to rise to the top on his own strength (though I look down on sleeping one's way to the top because it doesn't show your talent), so he understands Iwaki's distance from him. Chiba is the bad guy here, not Iwaki, so remember that. Chiba knows the truth and it trying to force Iwaki and Shou's relationship to be exposed with director Mochimune's movie. Because the roles are father and son, Chiba is hoping that the media and the acting world will realize how much Iwaki and Shou look alike and is also hoping that Shou messes up with the pressure of costarring with his father to the point of revealing their true relationship. I just hope that Iwaki can keep it together after finding out that Shou slept with Chiba. Please don't blow Iwaki-san!!!!

well first of all i'm not saying he must act like a father instantly but he has to take responsibilty for his kid, it's not right to ignore him like that, he can take as long as he wants to process the idea of him having a son but he's not even trying to be a dad, Katou is being around him so why can't his own father be, second of all he doesn't even has to say it to the world, at least he can be close to him advising him on what he should do privately & if it wasn't for the last chapter i would've been more cruel with my words, i feel that there's a possibility he might change his attitude towards his son.
& of course i know that Chiba is the f****** A******,but right now i'm more concerned about the way Iwaki treats his son. i can't agree with you nor Iwaki's ways, he just pisses me off with the way he's handling this matter.

Iwaki cares about Shou. When he first found out that he had a son, he felt guilty for not knowing. He's not ignoring Shou to be spiteful. He's ignoring Shou to protect him. Protect him from the media, which can have a negative influence in Shou's rise to fame, and protect him from the people who work in the field. They might treat Shou horribly out of jealousy because Iwaki's his dad, and they might feel that he's getting special treatment. Iwaki wants to help, but Shou wants to do it alone, so he's helping by playing the stranger role. Consider the possibility that pretending to be a stranger is also hard on Iwaki. He's the type of guy to take responsibility for his own, so you can tell that he's hurting not being in Shou's life. He even has Kato watch him because he can't. You said "Katou is being around him so why can't his own father be?" Well, remember that Iwaki is the president of a different company than where Kato works, and Shou is apart of Kato's company and even shares the same manager, so generally Kato would be able to see Shou more. Iwaki is not only the president of his company and is in charge of dozens of actors and managers under him, but he also has his own acting career to handle. His plate is ridiculously full (which brought on his collapse in earlier chapters), so you can see how hard it would be to see Shou outside of work. Just know this, Iwaki is very caring when it concerns Shou. If he wasn't, he wouldn't have reacted the way he did when he realized that Shou slept with Chiba. If he wasn't so caring, Kato would have told Iwaki what Shou did immediately, but he knew that it would have killed his lover, so he didn't tell him. You said, "but he's not even trying to be a dad," but in reality, no one can assume a role they never had before. It would feel forced or fake and neither Iwaki nor Shou wants that. That's like asking a sperm donor who just met a kid claiming to be his to try and act like a dad. It would be unfair, just like it is in this situation. In order for them to have a relationship, I do agree that they have to build one, but right now would be too soon. First they should build a relationship as co-actors and work from there. Although after the last chap, things might explode.

Why should he have to take responsibility? The woman never told him, and had no intentions of telling him. She even got married and another man raised him instead. and it would probably have still been a secret if the son didn't get suspicious. Plus the son is not some little kid. He is old enough to know that the man who raised him is his father. It doesn't have to be some man who happens to share the same genetics. Besides the mom still wants nothing from iwaki. Why should iwaki suddenly have to be a father to a person who is practically an adult. Now if they decide to build a relationship great. But your making it sound as if iwaki knocked up the women and left her once he found out she was having his baby and was refusing to take responsibility for it.
i'm still very annoyed that Shou slept with that old monster & i'm more annoyed that Iwaki is freaking ignoring his own son, but i thought he already knew about his son sleeping with that "thing", i'm now curious to know how he's gonna handle it & how he'll react to it. he better make up for his previous acts which i'm not so fond of, i want him to act like a parent & make Shou feel like he has a decent parent as well. he better he better he better !!!!!!!!!! or else.