|“||To us... Our purpose in the "Old Border" was to connect this world to the neighbors.||”|
Before it became publicly-known, Border was a secret organization with the purpose of being an intermediary between ‘Earth’ and Neighbors. To realize this goal, Border made an Alliance with three Neighbor nations where each vows to protect each other in the case of an invasion by hostile forces.
During its peak, Old Border has 19 people within its ranks. However, about five years before the start of the series, one of the allied nation was invaded by a hostile nation, and when Borders sent its forces to assist, 10 out of 19 members died, with some became Black Triggers.
Following its separation, most of its foundations were taken by Tamakoma Branch. This includes the building it uses as headquarters, the emblem and its goal.