The story revolves around "diclonii," a group of humans born with telekinetic abilities and horns on their heads known as "vectors." The strength and quantity of their vectors vary, granting them the power to deflect or stop certain bullets. However, as they age, these abilities often lead to violent tendencies, starting off playfully in childhood but growing into a deep hatred towards humanity.
Diclonii can reproduce naturally, while "silpelits" are the offspring of an infected human male. Interestingly, only males can pass on the gene, and all diclonii and silpelits are female. These mutations are often subjected to inhumane experiments or kept in isolation in an attempt to control their spread.
The main character, Kouta, is a non-mutant living amidst the chaos. His life becomes intertwined with Lucy, the primary antagonist and a pure diclonius with a traumatic past. Despite her desire to destroy humanity, she develops a connection with Kouta. The director, Kakuzawa, is another diclonius descendant seeking to mate with Lucy to create a true diclonius race and eliminate humanity.
Kouta and Lucy's intertwined lives go back to their childhood, with a tumultuous history. With the virus spreading across Japan, the fate of humanity hangs in the balance. Who will uncover the truth and hold the key to saving the world? Note that there are six additional chapters in the book.
