Itsuki is a kind person who would not be able to turn down a request for help. One day, he found out about his classmate Rushia’s secret. She is called the most refined, beautiful and intelligent Yamato Nadeshiko in the school, but she is actually a foreigner with exactly the opposite personality!? Her brother Isaac asked him to advise her on how to become the Yamato Nadeshiko that she aspires to be. He agreed not because he was asked, but because he wanted to do it for her. Later, the other girls around him all saw the mysterious blonde-haired foreigner clinging so closely to him and began to make their moves as well with the threat of a new rival.