The Organisation

The Organisation (ザ・オーガニゼーション Za Ōganizēshon) is a secret underground villain organisation, similar to the League of Villains who operate in a different part of Japan. It operates in secret using The Eternal Summer as a front, and act as the primary protagonist group of the Our Villain Organisation world. The Organisation was founded by Nocturne for personal reasons, and he acts as the Organisation's leader and co-ordinator.

History
What would then become the Organisation started when Nocturne employed the hero killer Keisuke Darashima to the Eternal Summer after defeating him in combat, making him the first member of the Organisation other than Nocturen himself to join the group.

Kumokyo Ichishi then joins the group after being found by Nocturne, having used her quirk to crash through a wall. This makes Kumokyo the most senior playable character, despite her actual age.

Keiko Ketsueki and Michiko Yuzuki join sometime after Kumokyo does, likely with Michiko joining before Keiko does due to her backstory. This also makes Keiko and Michiko likely good friends, as they have similar interests and have been together at the Organisation for a reasonably long period of time. Moka Yugosora and Kagami Henemi likely also join at some point during this period of time.

Shojirou Atsuki likely joins sometime in the middle of the Organisation's history, being one of the few members who joined not out of philosophy or criminal activity, but simply because he was actually looking for a job. Aoki Gahara was sourced using information from Slime-chan and approached using Nocturne's standard method of anonymous messaging - this makes Aoki more of a junior member, as at this point the groundwork for the Organisation and the Eternal Summer has already been laid down. He likely hasn't been in the Organisation for long either, as his existence is supposedly constantly being forgotten by Nocturne himself.

Shino is placed as the most recent addition to the group, as he is only formally introduced as an inductee during the first canon event, The Warehouse.