The story begins with a plutonium which is stolen from nuclear facilities. The terrifying scenario one can think of is probably terrorism. An even more frightening aspect is that "Nine" and "Twelve", which make thefts are not any different from any high school student. Considering contemporary events, you get more curious about the story.
"Nine" and "Twelve" quickly manage to escape from the facilities and before they escape they write "VON" on the ground of the facility. Later, they come to Tokyo and go to school like normal people. However, we manage to accumulate some information about the characters by the"flashbacks" that are often appeared. We learn that they used to live with other kids in a foundation but they escaped from there. In general, they feel revenge and regret.
A third person gets involved with these smart kids. I don't want to give spoiler so I just want to say that she was just in a wrong place at a wrong time. That's how she gets involved.
The two young men continue raising anger and violence on Tokyo with unusual methods by sharing videos. In particular, they give references to ancient Greek civilizations.
Too many things seem attached to each other in a frightening way. It's actually both frightening and exciting. You get more curious as you watch it.