Satoru Yotsumura

Yotsumura is a tall, powerfully built man past his youth, with tanned skin and a rough goatee framing a hard-set mouth. His black hair sits unkempt beneath a cream bucket hat that shadows weary, unfeeling eyes, brown in the anime and yellow in the manga. He typically wears an orange polo under a dark jacket with brown trousers. A clash with Shishiba tore open one cheek, leaving a lasting scar that echoes the one he once dealt his former pupil.

Sparing with words, Yotsumura stays unnervingly composed in a fight, treating even life-or-death clashes with detachment. Yet under that cold surface lies a father's love: he doted on his young son Amane, cradling him as an infant and passing down his own weapon, and he was prepared to kill his wife to keep the boy alive. What drives him now is a longing to move through the world in the open again, the reason he wants the JAA torn down, though he keeps his distance from Slur's cause and rejects the notion that its followers are true revolutionaries.

In his prime, Yotsumura helped found the Order beside his friend Kindaka while lecturing at the JCC. He eventually retired, married a fellow assassin named Shino, and fathered Amane. Tasked with rooting out a plot against the JAA's chief, he discovered that Shino herself was one of the conspirators, having wed him and borne his child purely as leverage. When she pressed a blade to their sleeping son, he cut her down in a single motion, only for Amane to wake and watch his mother die. The boy came to despise him. Framed for the chairman's later assassination and stripped of his Order rank, Yotsumura was marked for death and vanished into hiding in Kyoto.

Along the way he mentored the deadpan Shishiba, dragging him along on jobs and shaping him into a killer. Years later, Yotsumura resurfaced at the head of a band of assassins who loathed the JAA, personally cutting down dozens of its members and wiping out several of its companies, all with a bladed three-section staff keen enough to shear through steel. That campaign put him against the current Order, and a brutal duel with Shishiba ended with him gravely wounded and thrown into a river. Nagumo pulled him out and pressed him into service as a supposed dead man, a hidden agent set to dig into the death of Rion Akao from within the JAA. His investigation turned up a jarring revelation: the billion-yen bounty on Taro Sakamoto had been placed by Rion herself. Later still, he stepped in to guard Sakamoto's group when Oki attacked, standing with the reunited veterans of the Order.