Maki raised her son Kousuke single-handedly. Taking advantage of his growth, he remarries the man he is dating. Recently, for some reason, I can't help but worry about Kousuke. I couldn't help but wonder myself that I was starting to have bad feelings for my son. One day, a letter comes from the hospital where Kousuke gave birth... It was about Kousuke not being his own son. Ever since he was young, Kousuke has secretly harbored feelings of the opposite sex toward his mother.