Espers, humans who have the ability to control the ubiquitous phenomenon known as "mana." Mana is an unknown entity found everywhere and inside every living creature. Controlling mana grants espers access to unbelievable powers, normal people can only dream of.
At a certain university district, located at the heart of the city of Los Santos, southern USA. Yeng Renhua is an aloof and seemingly unapproachable girl, but underneath her pretty face, a dark ugly secret looms. Two years ago, she was regarded as one of the most prolific killer espers in the crime world. A victim of circumstance, she had no choice but to commit killings as a child assassin in order to survive. Eventually, she was no longer able to stomach the life of murder and chose to leave it all behind. Now she's on the run from her former benefactors, the Jiang crime syndicate.
Now, the ghosts of Renhua's violent past has come back to haunt her, but thanks to a strange twist of fate, she's found help from the unlikeliest of people. Hunter Clemens; a timid and seemingly unreliable 18-year-old engineering senior at her university, an all-around "normal" kid.