One day, Yusuke kisses a girl accidentally. The girl is Noel. She comes from the Devil World, where a kiss is the symbol of marriage. As a result, Yusuke is forced to marry her! Unexpectedly, Noel and her family move into Yusuke's house and start to live with him. To win his love, Noel decides to become an angel for him. But there is another girl whom Yusuke has secretly admired. Yet, Yusuke gradually begins to take care of Noel, an innocent and naive girl.
There is a hidden secret behind the scene; although Noel is not aware of it yet, she is one of three-divided Angel's souls. In order to become a real angel, she has to find two others and merge into one. However, once they merge, each soul will vanish. While Yusuke sorts out his feelings, delegates from the Devil World appear to prevent Noel from becoming an angel.