Oh, my god, that was an awesome story! I've read quite a few of Yamamoto sensei's works, but this one is definitely one her BEST. At first I was kind of confused by Chris's appearance (he looks really young despite being 24), but it didn't take long time to get used to it, and even though he's clumsy, he usually acts and thinks his age. At first Wataru came off as the cool and cold ice-prince, but he really isn't that (we can see that from the interactions with his friends, especially Rei). The humour is great too, there are really funny moments mixed with slightly angsty thoughts and scenes.
What I loved the best is the fact that they don't fall in love with each other immediately in the first chapter - no! With the two volumes, the pacing is slow (there's not even much romance in the first volume), but not boring at all. We can follow with our eyes and hearts how they stand up for each other after the tragedy in the family, how they get used to each other, how their like and love (and I mean the purest brotherly love) forms and later turns into romantic love. I wouldn't call that yaoi by "normal" means, it's mostly sweet shounen-ai; but that doesn't mean we don't get a final, sweet love-scene to satisfy our craving hearts. 😉 Oh, but the kissings! I believe they were the best. Not too much, just exactly how much the story needed, and all of them made my breath twitch.^^
What's an other very strong part of the manga is the two supporting characters, Yamada and Rei. (Chris' senpai was okay too, but he didn't leave such a strong impression in me.) You really will grow attached to them, they're so real and so human.
I honestly felt sorry for Yamada for his hopeless one-sided love for Chris, even though I always wanted Chris together with Wataru. And it was so great to see that both he and Rei punched Wataru hard in the face at the end! :D Yeah, the guy deserved that much, and it gave yet another reassuring and realistic feeling to the story.
BTW, it would be great to read a sequel to Yamada and Rei. I'm sure they would be awesome together.^^
Maybe the only bad thing I can point out in connection with them is that because of the three students' friendship with Chris, the man couldn't really give off the aura of a teacher.
What else is there? The art is cute, but not in the shoujou-ish uber-kawaii sense. It was nice and clear, expressive, especially the gestures and mimics. And oh, the eyes. If you've ever read from Yamamoto-sensei, then I don't need to explain. 😉
All in all, I really enjoyed this manga and I'm sure any BL-fan (maybe with the exception of those who don't feel comfortable with step-sibling love) would feel the same after reading it. Strongly recommended! 😀