Maki raised her son, Kosuke, with her own hands. When he grows up, he remarries the man he is dating. Recently, for some reason, I can't help but be curious about Kosuke. I couldn't help but wonder that I was starting to have bad feelings for my son. One day, there was a letter from the hospital where Kosuke was born. It was about Kosuke not being his own son. Kosuke, who has secretly had feelings for his mother of the opposite sex since he was a child, hugged Maki as soon as he found out that he was not a parent and child.