A mysterious Phenomenon changed this world forever. In the supermetropolis E-City, located somewhere in the territory of the former United States, monsters have bred.

E-City is divided in half. To the north is the territory of "big boss" Kellum Harker, and to the south is the territory of militant leader Henry Flynn. Three adopted children have become real weapons for Henry - teenager August, his older brother Leo and sister Ilse are monsters who steal souls with the help of music.

And widower Kellum Harker, in addition to his monstrous retinue, also has a daughter named Kate. Infant Terrible Kate desperately craves her father's attention. After another prank, the girl is transferred to a new school, where August finds himself on a secret mission - he must gain Kate’s trust and provide Henry with information.

Kate almost immediately guesses who August is and wants to present your father with a living gift. But soon the situation changes dramatically and Kate and August face a fateful choice.