In the distant future, after the discovery of a psionic-type brain hormone, humans develop extra-sensory powers, changing the face of the world forever. At the dawn of this new era, strange mutants called "Others" and with a certain appetite for human brains are literally falling from the sky. Very quickly, the world realizes that only extreme measures will be able to overcome these creatures, insensitive to conventional weapons, and that its only chance of survival lies in beings with ultra-developed extra-sensory abilities called "psionics". Since then, the BEA (Brigade for the Extermination of Others) has been recruiting all the psionics it can find to constitute humanity's last line of defense. Experience two stories, choosing to start with that of Yuito Sumeragi, a dynamic young recru.