Rib cage
The rib cage is the arrangement of ribs attached to the vertebral column and sternum in the thorax of most vertebrates, that encloses and protects the heart and lungs. In humans, the rib cage, also known as the thoracic cage, is a bony and cartilaginous structure which surrounds the thoracic cavity and supports the shoulder girdle to form the core part of the human skeleton. A typical human rib cage consists of 24 ribs in 12 pairs, the sternum and xiphoid process, the costal cartilages, and the 12 thoracic vertebrae.
Spiral: The Bonds of Reasoning
Some thirty years ago, a man called Yaiba Mizushiro was born with one rib missing from his right ribcage. Like Kiyotaka, he excelled at everything he chose to put his mind to. When he turned twenty-three, Yaiba started his own secret society, which swiftly grew powerful enough to manipulate world events. Citing boredom, Yaiba initiated the "Blade Children Project": using in vitro techniques and his DNA, he created eighty children, and had a rib removed from each of them at birth as a mark of their relationship to Yaiba. These Blade Children 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 split into three parties over the Blade Children Project: