The Blade children are the mystery of the series/manga. They are cursed children that few know about and are being pursued
by so-called Hunters. One of their main facial features of the Blade Children is their cat-like glowing eyes. They are also
missing a seventh rib bone on the right of the rib cage. All their fathers are unknown.
The story presented in the anime never reaches a point where the nature of the Blade Children is explained. The anime
only offers a comparison to Cuckoo birds. The implication being that something not human deposited the Blade Children in human
"nests" to be raised, similar to how Cuckoo birds deposit their eggs in the nests of other birds. The anime also
suggests that Cuckoos go destructively and violently crazy toward the end of their lives.
The manga explains why the Blade Children are cursed and their origins:
A man called Yaiba Mizushiro was born sixteen years before Narumi's older brother, Kiyotaka. He was born with one rib
missing from his right ribcage. Like Kiyotaka, he excelled at everything he chose to put his mind to and was the darling of
the world for the first twenty-odd years of his life. When he turned twenty-three, Yaiba started his own secret society, which
swiftly grew to gigantic proportions, able to manipulate world events. Citing boredom, Yaiba initiated the "Blade Children
Project".
Using in vitro techniques, he seeded his DNA and created a total of eighty children. These children all had a rib removed
at birth to signify them being of Yaiba's blood. They were cursed in the same way Yaiba was: they would grow up as geniuses
in their own right, but one day their blood would awaken murderously and take over their self-will, becoming avatars of Yaiba.
Yaiba's organization was split into three camps over the Blade Children Project:
*
Savers. The first group, Savers, were supportive of Yaiba and desired to create more Blade Children.
*
Watchers. The second group, Watchers, were neutral. They wanted to observe the first batch of Children and gather
results first.
*
Hunters. The last camp were called the Hunters. They were against Yaiba, and tried multiple times to assassinate
him. Yaiba had the devil's luck, and everything failed, from bullets to bombs.
When Yaiba was thirty-six, one Japanese man came out of nowhere and easily killed him: Kiyotaka Narumi. He was the counterpart
to Yaiba: if Yaiba had been a destroyer, Kiyotaka was a creator. Yaiba had intended to remake the world literally in his own
image; with his death, the Blade Children project was halted. Kiyotaka had his hands full trying to stop the Hunters from
killing all the Children, while trying to check the Savers at the same time.
The counterpart metaphor does not end there. Since Kiyotaka had a brother who was like him but not him (another creator),
Yaiba also had a sibling: Hizumi Mizushiro, Ayumu's mirror image, the one who will awaken the blood of the remaining Blade
Children.

Blade Children |

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left to right: Eyes, Kanone, Ryoko, Kousuke, and Rio |
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