 By the end of the series, all relationships and emotions are resolved, and Kouji and Aoi return to the Ryvius as an official couple.With intelligence, strength, and intuitions superior to his brother's, 15-year-old Yuki Aiba has no need for his older brother Kouji, Kouji's friends or Kouji's patronizing - indeed, fights are inevitable whenever the Aiba boys meet face-to-face.A lone wolf, it is hard for him to live with others.