Older brother Kenichi and younger brother Takashi had not seen each other for a while, but they meet at their estranged father's funeral. The father had moved to a small town and remarried and has a daughter, who is supposed to be their half-sister. Her whereabouts are unknown, as she left home at a very young age. One of the brothers mistakenly meets her, under very strange and disturbing circumstances...

In 2050, a nuclear war broke out all over the world. With the help of a military industry family, Tanahashi, Japanese Imperial Army plans to conquer the world and sets up new government NEO YAMATO. In order to against the tyranny of the new government, a rebellious army of the government fights for peace.