I don't think it's right to say that Keiichi hates Rio, because Rio is his nephew after all. They're blood related. I think he's just jealous of Rio being too fond of Shingo and so cuddly with him. And for he's brother and everyone else, well I guess it's just Keiichis being protective a bit too much XD it's still cute tho
I think the only reason he isn't that mean to Rio is that they're related and he's still a child. Well I think everyone feel diffrent, I don't think it's cute to act like this ^^°
I agree with ppana, Keiichi doesn't hate his nephew neither his brother. He just become a little bit irrational when it comes to Shingo. The only idea of losing him terrifies Keiichi and as a result he may act sometimes like a jerk. But after re-reading all the saga (till the beginning) I'm prety sure Keiichi is a very caring lover, uncle and even brother. The proof is that he's accepted the BBQ with everyone (even Hasumi). That's a real big progress ! ^^
Why is he so possessive? I don't think they will last long like this. I really live Shingo and I know he dislikes it to.... I mean Keiichi hates Rio (who is the cutest baby boy ever!) and his Brother and everyone who likes Shingo. It really makes me angry...