School au. In the "Ability Laboratory", the best scientists examined the most dangerous abilities. They worked on a dangerous one named Arahabaki. Project A5158 is a boy named Nakahara Chuuya, he is the materialization of Arahabaki. Everything he wanted was to have a normal life : have a family, go to school, have friends, ... One day he escaped from the "Ability Laboratory" and, so that no one would recognize him, he took a girl appearance. He gonna meet a brunette boy, in first he gonna hate him, but it is really hate what he feel? How far will they go to be free?...

While at odds with each other, Dazai Osamu and Nakahara Chuuya search for a true light in a world where evils exists everywhere.