Ichiro Inuyashiki is an adult in his 58th year, with no friends and a carefree familyof him, his wife and children; The day he was ruined by a mysterious explosion in a public park, then his body is replaced by an incredibly powerful mechanical body physically identical to the normal human body this was caused by some alien entity during the explosion. On the other band, a teenager involved in the same explosion, the young Hiro Shishigami gains the same abilities as Ichiro.
