Yukari raised her son alone and had secured a job. Four years ago, on one particular day, she had a relationship with her son under the promise that it would only happen once… Since then, Yukari's heart and body have been aching. One day, her son invited her on a hot spring trip as an expression of gratitude, and they decided to go just the two of them… The mother, who cannot forget that day, knows it's wrong but can't stop herself. A new forbidden relationship begins between mother and son… An incest story!
