In the summer of 2016, an unknown alien organism invades Earth and annihilates 20% of the human race in a span of one month . However, survivors of this virus were either transformed into a hideous creatures called "Worms" or into super-humans called the "Heteros". The heteros form a protection agency called the "ISO" to fight the worms. Haru, a young hetero but also a mischievous trouble maker, wants to join this agency in the fight. But it's no easy road.

The hit series from EunSong returns with officially updated artwork, chapters, and additional scenes! With the sudden outbreak of a deadly virus, humanity is thrown into chaos. The few who survive it are either transformed into horrible cannibalistic creatures called "Worms," or super-humans called "Anomalies." Haru, a young Anomaly student at New Seoul High School, dreams of joining the prestigious "ISO" - an organization formed to fight the war against this virus. But the future in store for him is nothing like he imagined...