Hikaru Takabe used to be the class loner. She was that girl who always kept to herself and would have rather had her headphones on at all times, even during class sessions. She never dared open her heart to anyone. But after she was obliviated by a meteor and rebuilt from her DNA up by a cosmic creature called "Horizon" her outlook on life took a quick turn for the positive.
Now Hikaru will have to host another inter-galactic entity within her. Now the interstellar mass-murderer "Maelstrom" has settled inside her along with Horizon. But this completely new life-form not only has brought less privacy into Hikaru's life, but it may have changed the direction of evolution itself. As if sensing the earth's unusual state, a new existence proclaiming itself "the moderator" suddenly appears in front of Hikaru. According to him the earth is about to attempt a "macro evolution" in extreme chaos, so that he needs to correct the process in case that it causes disorder of the universe.