Maki raised her son Kosuke on her own. As he grew up, she decided to remarry the man she was dating, but... Recently, for some reason, she couldn't stop thinking about Kosuke. She couldn't help but wonder why she was starting to have negative feelings for her son. Then, one day, she received a letter from the hospital where Kosuke was born... It said that Kosuke was not her son. Since childhood, Kosuke had secretly had feelings for his mother, and as soon as he found out that they were not mother and son, he couldn't help but embrace Maki...