This is the first yaoi that I've ever read, but I've been reading manga for a long time. There were some things that I both loved and hated about this series, but my biggest qualm would have to be with Tatsuya's character.
Sorry, but from the perspective of someone who has never read yaoi before, the thing with the baby goes beyond societal issues with gay relationships and has more to do with Tatsuya's selfishness than anything. That was Tatsuya being stupid, selfish, and completely and totally disregarding the fact that he was betraying the trust of the one person who had given up everything to be with him. I don't care if he did it out of curiosity or pity, he still cheated on someone that he was in a very serious relationship with. Although I realize that people make mistakes and that things happen like that all of the time, that doesn't excuse it or make it any less wrong. He cheated and broke his lovers heart....bottom line. I wasn't expecting things to be picture perfect and pretty here. I even appreciate the fact that the mangaka decided to take a more realistic route with this one, but there were some serious trust and loyalty issues here that I just couldn't get over. Shinozaki went above and beyond, trying to construct a good relationship with this person, only to have him cheat and get some random person pregnant. Then he married her and made a happy, friendly life with this person after having betrayed a near lifetime's worth of trust with something as ridiculous as pity sex. There was nothing stopping him from telling her no.
Yes, this manga was realistic and all that, but it doesn't change the fact that Tatsuya was a selfish, untrustworthy ass.
I absolutely loved how things turned out with Tatsuya's son and his best friend though. To some, it might have been a bit disappointing, but I think that the author made the right decision. She very expertedly demonstrated how tipping the scale on the thin border between love and friendship can change everything, so I enjoyed seeing this story told with two different out comes. That was the case if you really just think about it.
All in all, this series was very realistic--how surprising! The mangaka actually managed to make me feel just as happy, angry, sad, and confused as the characters in this series. I still wanted to strangle Tatsuya up to the very end and, quite honestly, I couldn't stop myself for disliking him after he did what he did. However, this was a pretty good on overall.