Wow this one was a tough one... but it did get better and actually had a ending that was quite a bit satisfying.
From wiki (and better than anything I could do):
"The story centers around Erika Shinohara, a 16-year-old girl who tells her friends tall tales about her romantic exploits, but she actually has no boyfriend. She says that a handsome boy in a candid photo is her boyfriend, but it turns out that boy is a schoolmate named Kyōya Sata. She has no choice but to make him her fake boyfriend. However, Sata may look like a sweet person, but he is actually an ultra-black-hearted sadist. Sata takes advantage of Erika's weakness and treats her like his dog"
And the last part is the key "treats her like his dog".
Sata is fucking BRUTAL at times... I mean kick a girl a in her twat and make her cry plain fucking evil. It was actually hard to watch as Sata just grinds up Erika over and over and over.. fuck I wanted to punch my t.v. I was so angry. Just like any abusive relationship (and fuck is it ever) Sata also does and says some pretty powerful and meaningful things to Erika.. maybe its his true feelings, maybe just to string her along, but man the mind fucks this dude comes up with can twist your mind. Turns out Sata has is simply repressing emotions from a broken home... but his family is pretty normal.. only he is twisted.. and eventually warms up a bit... a very little bit.
Its good story, and it swings from both sides: Sata crushing Erika with just pure evil acts, and also doing and saying some thing that would get my panties wet... if I wore panties, that is. So just be ready for the first 6 episodes to be painful to watch and marvel at how Ericka doesn't stick a knife in Sata's heart ala Saionji in School days (ha! fucking right, an anime reference in an anime review!)