Michiko and Shinichi became a couple since their school days, with Michiko giving birth to Shinichi while still a student. After graduation, she started a business with her husband, leading a busy life during which she could rarely spend time with Shinichi. However, whenever they were together, Michiko doted on him endlessly, and he naturally clung to her affectionately. This relationship continued even as Shinichi grew into adulthood, eventually evolving into a physical affair. Since her husband's presence at home made intimacy difficult, they began taking trips together, allowing them to enjoy each other freely without anyone watching.