Mayu lives with her husband's parents. By coincidence, her father-in-law was her former teacher in high school. During her school days, Mayu had feelings for her father-in-law that were more than just respect, so she devotedly cared for him. In order to cheer up her weakened father-in-law, Mayu literally puts her body on the line to care for him. Before she knew it, her feelings of love for her "sensei" made her body heat up, and she fell into a pleasure she had never felt before.