Nounai Kanojo - Usodere!

Since the main character lost his parents when he was a kid, he now lives alone. One day, his grand-father, a man of property, tells him to move to his house. He is confused at first, but he decides to start his new life. He also transfers to a new school, but he is actually one and only male student. Every girl is interested in him because they think he will inherit his grand-father's property sooner or later... Like this, a battle for him starts...