I'm really rather sick of reading hateful comments, especially when Madarame Hiro is a talented and original mangaka. So my first recommendation for Scarlet is to (if you're in the habit of doing so) quit trying to relate fiction to reality. Scarlet is dramatic, passionate and very, very unrealistic. Please do not expect anything more than that. After all, we're reading yaoi!
Yes, Scarlet's first story does touch on some quite controversial topics such as infidelity, violence and rape. Ryou is the beautiful, much admired and socially awkward half-Japanese classmate of Akio. After striking up a friendship, they begin a relationship which is difficult from the very beginning. Read onto the spoiler for a more in-depth summary.
Ryou, because of the social stigma attached to being a half-blood and his naturally shy and awkward personality, is easily forced into flings with the many women that hit on him. Akio, in my opinion, is just as much to blame for their troubled relationship as Ryou. Though Akio doesn't cheat, he never speaks to Ryou about his affairs until one particular woman appears on the scene and virtually forces Akio out of the equation. After the ending of the first chapter, where Akio believes that Ryou's act of violence is the proof of his love, it's quite clear that both of the characters are rather messed up.
I'd also like to mention that I can name more than four dozen other yaoi titles with a cheating/violent seme and a pushover uke. Is Scarlet really something to be so shocked about when it's an oft repeated storyline? One quite clear comparison can be made between Scarlet and Let Dai. Let Dai was tremendously popular in the yaoi community and pretty much all of its characters were even more messed up than the first couple featured in Scarlet and the quite long series was even more violent than this one.
Lastly, the overall theme of Scarlet (through the three couples featured within) deals with stories of unbalanced relationships. The semes are tall, handsome and very popular and their uke partners are short, timid and under-appreciated. Though the last two couples feature no hint of violence, the relationships are just as awkward and messed up as the first.
I really do have to insist that you do not neglect to read Scarlet because of the reviews of haters. If you cannot differentiate between fantasy and reality, you shouldn't bother reading. Madarame does a wonderful job of creating an intense drama - just look at all the comments! I'm quite sure that none of the many readers who enjoyed this are rapists or vicious abusers, nor in the support of such people. However, just like another book you might read, or movie you might watch, Scarlet deals with some controversial issues and tries to show you, without influencing you, what happens to these characters when something like this happens.
Madarame's authorial voice is non-existent for a reason. She wants you to have your own reaction to the story, not feed you a reaction herself. Since when do you have to love every character you read about? Why do writers have to create characters only to please you? To be honest, I really didn't like Ryou or Akio and I don't support their actions in the end, but that doesn't mean that I hate the story. In fact, I love it. Why? Because it does a fantastic job of what it's supposed to do and that is to reveal its story, develop its characters and leave me to decide whether I like them or not. I love Scarlet because it is bad, not because I support what happens in it.
Scarlet, though the first couple is frustrating, has its own wonderful merits. The artistic style is absolutely gorgeous and the stories vary from intense drama to light-hearted comedy. Given that this is Madarame's first publication, I think she's done an amazingly good job of tackling some strong issues.