The mangaka tried to mix typical storyline formulas without actually thinking about the themes she was introducing. Chapters 1-2 and the extra, yaoi, with a light bdsm twist. Too short to make it fun. Chaters 3-4, hastily thrown together, no depth, badly edited. Chapters 5-6, an emotional firestorm treated too casually to do anything but evoke intense feelings in the reader as they react to themes that were not developed.
Chapters 5 and 6 are such a complex issue that they might take volumes to present in a way that would engage the reader. It might be a romance, but it is a dramatic one.
Someone made a comment "and obviously he really wanted it even back when he was a boy! gah. that just goes over an internal line i have, because this is an excuse actual pedophiles use. " I vehemently disagree with this. There was no implication that he "wanted it back then" that I could see. Also, while a pedophile may convince a child that he 'wanted it', in order to tie it to this story, the teacher would have had to know the boy was molested and the teacher would have had to leverage it, to tie it to pedophiliac intent. That did not happen. What happened was that the teacher was pushed, and like in any number of yaoi manga, he pushed back.
In those last two chapters we have a criss cross of hard core reality being mixed with hard yaoi. I have read similar stories, with the exact same reference points and they were given pretty high ratings by the reader. But I think because the mangaka added one element, she is going to get an intense emotional reaction from the reader. I'm reacting to the viciousness of the reviewers and how off target they are. This was a stupidly handled story. The element is that the uke spouts rabidly homophobic statements and even harasses the seme viciously. This sets a tone that does not fit the seeming intent of the story, a romance. It is too emotionally intense to transition into a love story without massive development and time.
The story follows a typical hard yaoi theme. By eliciting the mixed bag of emotions that comes with child molestation, rape and someone who reacts in one of the typical ways to it (which is rarely addressed in this medium), the mangaka opened up a huge story and then dropped the ball. The mangaka did not consider that she showed someone realistically reacting to being molested as a child and then tried to shoehorn it inta a happy ending. This work should have been several mangas or volumes all on its' own.
By the way, what I mean by realistic, it is not uncommon for a rape victim to despise sex. A woman raped by a man, can very easily become unable to have relations with men. A boy raped by a man, can become a radical homophobe. The victim becoming a persecutor of others that he sees as a focus for his pain. There are quite a few other reactions, I'm commenting on the ones that were used.
If that rape/molestation was physically enjoyable, the guilt associated with it can be immensely destructive. Rape is violence to the body and the mind.
The boy in this story, may or may not have been straight, bi or gay. The implication from the story is that he was dating girls before he became involved with the teacher. Again, the mangaka didn't develop the story and either introduce the concept of him being bi, or becoming bi because his feelings were more important to him than the physicality of his partner. My guess is that the mangaka was following the typical formulas used in yaoi stories where the straight guy falls in love with another guy. Or the "I only can love one man, so I'm not homosexual" formula which is also popular in yaoi. She did not consider how that would mix with the intense concepts that she chose to throw into the story.
All in all, if a good writer took chapters 5-6 and used them as a synopsis, a very intense and memorable story could be told and it could even have a happy ending.