Ayumu tells Hiyono about the Blade Children and their distinguishing characteristic: all are missing their 7th rib on their right side. Meanwhile, two Blade Children are worried -- but not too worried.

Ayumu Narumi is investigating the disappearance of his older brother, Kiyotaka. When his search leads him to a shadowy organization known as the Blade Children, Narumi becomes implicated in the group's criminal dealings and finds himself accused of murder. With the help of his journalist friend Hiyono Yuizaki, Narumi sets out to prove his innocence, unravel the mystery of his missing brother and figure out why the Blade Children have become inextricably linked to his destiny.