Kizuki Osamu is Kizuki Rin's grandfather. During the first arc of the series, he was mentioned but never seen. In the second arc, he was first seen in a cabin deep in the suburbs of an unnamed country. He later revealed he wanted Joukyuu Kunitoshi to fight Houjo Kaneoto. Unlike most people in the Aiki universe, his forte is in medics, being able to disable Andrew by swiping needles through his knees and literally opening spots of pain from his past and present. In chapter 62 Joukyuu said to Kageyasu and Balboa that he is known as the greatest acupuncturist of this century.