Takahara Kouhei works for a space project where the life of his colleagues and himself is constantly in danger. The leaders of the space project have been long working on a clone project with the thought that that way they could rid humanity of unnecessary loss like people getting killed for things they can't influence. Of course, Kouhei gets involved in that project as a test subject where he is being promised that his memories and physical appearance won't change at all, and that if in case he'd die on duty his life would proceed within a clone of his. Scared of being denied, he doesn't inform his wife... only if he knew that the death angel won't wait too long for him.