Kyousuke Shiroyama
The story's main character. He is a Summoner, affiliated to of one of the Great Three Summoner Powers called "Freedom". He is given Award #902 for his remarkable talent, but he constantly suffers from his uncontrollable urge to assist those who ask for help.
Lu Niang-Lan (Ryu Nian Lan)
A Summoner who belongs to one of the Great Three Summoner Powers, "Illegal". She known by those who fear her as "Soushin Anki" (lit., "weapon concealed in a slim figure"), who can slaughter even experienced Summoners by using weapons hidden in her flesh.
Renge (older) and Higan (younger) Myounokawa
A pair consisting of a Summoner older sister and a Yorishiro (spirit medium) younger sister. They are currently on the run after failing their duties. Higan is separated from Renge and got lost, so Higan asked help from Kyousuke.
Incomplete translation:
Aika or Ayaka (not sure about reading due to many possible interpretations)
A Summoner who belongs to one of the Three Powers, "Government". She is a shut in who seems to call (not sure) Kyousuke "Onii-chan". Has a pet white liger.