Esper Union
"Protecting humanity from Miramon has always been the Union’s guiding mission. Founded by a group of pioneering Espers, the Esper Union is dedicated to uncovering the mysteries behind Miracles and ridding the world of the disorders brought by both Miramon and misusers of their newfound powers. Thus, the Union and its members have formed a network of quiet guardians around the world."
Shadow Decree
"Unlike the Union, the founders of the Shadow Decree have chosen to embrace the Miracles and their potential powers. This powerful organization regards the Miracles as gifts of the gods and their dangers an “unavoidable sacrifice”. Those of the Shadow stand on the side of a cause great enough to rewrite human history, or so it is believed, for which reason they must stand against the Esper Union."
Wanderer
"There are notable Espers who don't belong to either the Esper Union or the Shadow Decree, they act by their own rules and enjoy their freedom without any restrictions. However, several organizations less prominent than the Union or the Decree also find themselves here. "