Imports are major event in RJO stories, where new sources are added. After an import, possible magic present in source also starts to appear in Earth mundanes.
Import always permanently adds characters to RJO. In the beginning, there seemed to be some kind of balance of power in the imported characters, in that both heroes and villains would appear. In later imports this wasn't always the case.
For smaller imports, where the source isn't new, see Merger. However, some persons have appeared via sub-mergers, like Sly Cooper.
For 'reverse imports', where RJO characters visit other worlds, see Export.