Yuusaku also grew up together with Madoka and Hikaru and is in love with Hikaru. When they were smaller she told him that she wouldn039t be interested in him unless he became stronger and more masculine. Thus Yuusaku trained heavily in martial arts. By the time he achieved proficiency Kyousuke has arrived on the scene and Hikaru is headoverheels in love with Kyousuke. He naturally regards Kyousuke as a rival in love for Hikaru. Thus the relationship between Yuusaku and Kyousuke is a bit strained.