Eri 'Eddy' Yamaguchi was a scientist working on high-tech solutions for continuing human life in the face of a rapidly approaching Malthusian limit as well as a high premium on clean air. His funding was cut as he was looking for a healthy, strong young man to test his biotech on, and in a desperate effort to keep the government from shoving his prototypes into a box somewhere and vanishing it, he paid off one of his assistants to operate on him. His prototypes were 'installed' in his own somewhat out-of-shape body, giving him immense stamina bordering on regeneration, the ability to survive on almost no inputs, and access to a basic communication system (cellular?) in his head. 

Unfortunately, this left him mildly disfigured and a traitor to his country. He couldn't risk getting IDed, so he didn't dare get a job as a scientist, even for another country. But he could -- and did -- get a job as a samurai. He was born to the right kind of family, and had always been disrespected for his choice to become a scientist rather than a warrior. Well, now he was going to fulfill his blood destiny regardless of everything he wanted for himself and for the world. 

At least, until such time as he could find the means to scrape together an independent laboratory and create another set of prototypes. Provided, of course, that the ones in his body keep working well enough to keep him ticking until then...