Soujun Sa is the eldest grandson of Chuushou and matches him in blind ambition. He works with the Satsujinzoku to kidnap Eigetsu Tou and Koorin, whom they had mistaken for Shuurei. Believing that the group is under his grandfather's control, he attempts to shift their allegiance of their leader, Meishou, and gain their support for himself. Soujun is eventually killed by Sakujun, his next youngest brother, although he blames their third brother Kokujun for it.