On days when she is sick, on days when she has a tedious day job, on days when she has regular tests. On days when she is too lazy to go to school, I am called upon. I am a convenient substitute for the body of a girl named Sonao Aikawa, and that is me. I may look exactly the same, but my personality is a little different. I can't go out freely, I can't even make plans for tomorrow, I am a replica whose mission is to work for the original. I was supposed to be a replica but I fell in love.