A succession race breaks out at a school between Motonori, a son of the principal, and Rinko, his cousin. According to the former principal, the one who gets a son/daughter of heir will win the race. One day, Mana, a sick-room teacher, comes to the school. Due to her kindness and beauty, she soon gets popular among male students. The main character is Yuu, who is a dropout student. He falls in love with her and often visits the sick-room to meet her. He also starts studying hard not to flunk. Mana gradually falls in love with Yuu.... On the other hand, Motonori tries to make a baby with Mana, his fiancee, but she doesn't let him.... Yuu also gets involved in the race.... Well, will he be able to graduate from school...? What will happen between Yuu and Mana...?
