Sakamoto Days, Vol. 19 (manga)

When Slur takes what should be a lethal wound, he transforms…suddenly manifesting Akao’s personality! Sakamoto and Nagumo are baffled to encounter what seems to be their long-lost friend, and the trio attempts to flee from the JAA. But when they come face-to-face with their most dreaded opponent, the Assassin Exhibition of the Century arc reaches its climax!