Kareshi Kanojo no Jijou

Yukino Miyazawa is the perfect model student. Pretty, kind, good at sports, always at the top of her class. But she's not all that she seems. It's all an act of deception; she is really the self-confessed 'queen of vanity,' and her only goal in life is winning the praise and admiration of everyone around her.

When she enters high school, she finally meets her match: Souichirou Arima, a handsome, athletic, popular, and very intelligent young boy. Ever since he stole the top seat in the class from her, Yukino has hated him, and has been plotting on how to take back her former place as the object of all other students' admiration.

What she wasn't expecting, however, was that Souichirou, the very boy she hated, would confess his love for her. Or that he would find out about her deception—and use it to blackmail her!

Together, they discover that they have more in common than they knew, and they slowly begin to bring out each other's inner selves.

(Source: MU)

Included one-shots:
Volume 1: Tora to Chameleon: Yakusoku wa Isshukan (The Tiger and the Chameleon: A Promise for One Week)
Volume 4: Ashita Mata Mori de Aou ne (Meet Me Again Tomorrow in the Forest)
Volume 8: Abareru Ousama (The Raging King)