Tomomi, Shinobu, and Yurie Ono, are three sisters with a mysterious past that no person should ever know. As they moved in to Japan, the girls attend to U.A. High School because their mother use to go to school here before she drops out to marry their father. the girls soon makes friends with their classmates from class A, and of course rivals where they spend their everyday lives in Japan. So who are these girls? What is their secret? How will they adjust their new lives in U.A.?