Ichiro Inuyashiki is a 58-year-old man with a routine life, he works in a office, has no friends, and has a family that despises him and is always unconcerned about him. One day he receives the news that he has terminal cancer and has a short time to live, and to make matters worse, when he returns home he is involved in a mysterious explosion, but later his body is replaced by a mechanical one. On the other hand, a young man named Hiro Shishigami who was also in the explosion gets the same abilities, while Ichiro plans to help others, Hiro will bring chaos and destruction.
