Ai to Iu Na no Moto ni

Rosy is in a terrible predicament. According to her grandfather's will, if she doesn't marry, the historic mansion she lives in will fall into the hands of her greedy uncle. In order to fulfill the requirements of the will, her lawyer strongly recommends a contract marriage with her childhood friend Guard. Rosy is hesitant at first, but it's the only option she has to protect her grandfather's beloved mansion. She finally proposes to Guard, who also accepts in order to save the mansion. He's arrogant, ill-tempered and far from her ideal man, but as time goes on, she finds herself swept away by his charm, even though she knows he's only marrying her to get his hands on the mansion... Or is he?