Seiryū Kamiki, born Omata Kousuke, adopts the stage name "Kamiki" to honor his teacher, Kamiki Ryūgen, head of the Kamiki shamisen school. His playing is technical and precise, forming a deliberate contrast to Setsu Sawamura's emotionally charged style. Seiryū's performances demand flawlessness and strict adherence to tradition, embodying his narrative role as a perfectionist.

A prominent shamisen figure, Seiryū initially dismisses Setsu's abilities after witnessing an inconsistent performance. This encounter spurs him to challenge Setsu, aiming to provoke Setsu's full potential during competitions. Seiryū's analytical nature surfaces in his critical assessments, such as noting slack in Kaji's shamisen strings at a crucial competition moment.

His background intertwines with the Kamiki school's complex familial dynamics. Though not biologically related to Kamiki Ryūgen, assuming the name signifies Seiryū's profound commitment to the school's legacy. His exact age remains ambiguous, enhancing his enigmatic presence. Seiryū's character development revolves around his evolving rivalry with Setsu, a dynamic that pushes both musicians toward greater artistic growth.