She was slut-shamed for the way she looked and was even sexually assaulted by another student (he forcefully grabbed and fondled her boobs, not letting her get away) in broad daylight (the hallway in school), and no one stepped in, just saying that she was probably pretending not to want it. That's when the ML stepped in and saved her. He was already in love with her before then, and had been for a while. He had been watching her from afar and realized that those rumors were bullshit. He started looking her way out of curiosity at first, but it developed into romantic feelings. She fell for him a bit after he saved her. They went on a date, and she confessed her feelings, to which he asked her out. He was so happy that he forgot to tell her how he felt, but he told her when they finally did have sex (which she had wanted to do for a while during their relationship). She was shocked that he had liked her for a while before they started dating.
I loved that they were both virgins. I thought that made it cuter. He was a really good guy and saw her for more than just her looks. Although, he DID see her for her looks too. They were just awesome together, and will surely have a great future ahead of them. I will probably re-read it at some point. 9.5/10
Kareshi ga Shite Kurenai! Dogan Kyonyu Shojo no Yoru no o Nayami