Mimic

Mimic (ミミック,) was a guerrilla organization from Europe that escaped to Japan after committing a war-crime sometime during a past global war. Led by André Gide, Mimic intended to find someone to kill them as soldiers as one last bit of solace after facing disgrace and shame.

History
Mimic previously operated as a powerful guerrilla organization assisting in a previous war going on in Europe years before arriving in Japan. A small unit of roughly 40 Mimic men succeeded in taking down over 600 enemies. However, Mimic found out their attack became a war-crime: their orders were a decoy set up by their country, as the enemy and Mimic's home country arranged a treaty of sorts to end the war.

Allied soldiers were then sent to kill Mimic commandant Gide for his betrayal, leaving Mimic no choice but to retaliate against their former allies-turned-enemies. They took the latter ones' grau geist pistols and donned their military uniforms, mimicking enemy soldiers akin to being ghosts of the deceased. With nowhere and no one to turn to, some soldiers killed themselves. Those who survived sought people who could kill them as soldiers, such as the Order of the Clock Tower. However, the British organization drove them out of the continent, and Mimic eventually fled to Japan.

Mimic targeted the Port Mafia, given its infamous reputation as a powerful group with skilled ability users, hoping to find someone who could kill them as a saving grace after being shamed and disgraced. In truth, Mafia boss Ōgai Mori aided their illegal entrance to Japan in order to use them in his scheme of attaining a Skilled Business Permit from the Special Division for Unusual Powers. His plan involved having the Special Division seek out the Mafia, who would be Mimic's target adversary, amidst their chaotic encounters throughout Yokohama, knowing that the Special Division would see it as an opportunity of having the two illegal organizations take each other out.

Their methods were extreme, using a spy, Ango Sakaguchi, to infiltrate confidential areas of the Port Mafia's turf, though Ango was also a spy for both the Mafia and the Special Division simultaneously. Originally acting on Mori's orders to infiltrate Mimic as a mafioso, he also divulged intel to the Special Division. Mimic's onslaughts led their leader Gide to an encounter with Sakunosuke Oda, a low-ranking mafioso. Intrigued by Oda's ability, which was nearly identical to his own, Gide urged Oda to kill him and his members. However, insisting he would not kill anyone, Oda turned his back on them.

Mimic retaliated by kidnapping the orphans Oda took care of, killing them in an explosion in front of him after a brief pursuit. The shock drove the former assassin to abandon his no-kill policy and dreams of becoming an author for the sake of revenge. Reaching Mimic's hideout, Oda killed all Mimic members. During Oda's final confrontation with Gide, both of them were killed.

Ultimately, Mori's scheme worked successfully and yielded him the Skilled Business Permit for the Mafia as issued by Santōka Taneda. Moreover, Mimic's involvement with Oda's death led Mafia executive Osamu Dazai to leave the organization and caused an intense schism between him and Ango. After Gide's death, three Mimic remnants who were absent in their headquarters during the final confrontation were killed off by Akutagawa in an underground aqueduct somewhere in the Yokohama Settlement.