The Difficultly With Clones

Research has shown that reproductive cloning, especially on mammals leads to imperfect clones that often die young or live a life with deformities. This assumes of course that they actually survive to birth. Clones suffer this fate because while the base genetic material is the same, it is physically a different embryo. The fusion occurs between a gutted egg and another cell's nucleus. The process is difficult and often leads to a number of flaws. Beyond that unlike cloned embryos used for therapeutic stem cell treatments clones that are created to be living replicas have to survive until birth which leaves a huge room for error. For more information, Wired has a number of articles for those of us who aren't biologists or geneticists that are worth reading. In Spiral, the science behind cloning follows that of real life which creates the question why would individuals like Hizumi and Ayumu be created if it is so risky.

In the case of Ayumu Narumi it is plainly stated that he was created as a 'spare body' for his brother. Ayumu and Kiyotaka's mother was a famous concert pianist who lost the use of her hands in a car accident. When Kiyotaka inherited her abilities she wanted to be sure he wouldn't suffer the way she did. She went to extreme and illegal lengths to ensure that should anything happen to Kiyotaka they would have spare parts which could be used to repair him. Kiyotaka in a rare moment of unselfishness quit the piano so as not to subject the boy he came to know as his younger brother to that fate.

The matter of Hizumi Mizushiro is much harder to explain as it is never explicitly stated why he was created. By the time of his birth Yaiba had already chosen to become a devil. He already had created a number of children with superior abilities destined to become killers by the time they reached adulthood. Why would he need a clone? It is possible that he intended to use Hizumi to extend his existence and outlive Kiyotaka when they finally fought. That being said the Kiyotaka sixteen years prior to the start of the series was still a student who had no knowledge of who he would become.

The more likely scenario is that Yaiba created Hizumi as a replacement to defeat Kiyotaka in the event that he failed to defeat him on his own or perhaps he created him with the knowledge that the Narumi family was planning on creating a clone of Kiyotaka so that the saga of gods and devils came full circle. Either way Hizumi, unlike Ayumu was created with the purpose surviving to adulthood to continue Yaiba's legacy.