A tied up married woman - a librarian's masochistic fantasy

It's been three years since I married my husband, whom I met in a university reading club. Even though I was teased as an elderly couple since I was a student, my biggest happiest was to both read the books I liked and spend time relaxing. In the same repeated daily life, I compared myself to the female protagonist of an erotic novel and envisioned myself as a woman who was indulging in sexuality in my delusions. One day, I met that person who had the same habit of delusion and signed a contract. Without destroying each other's lives, they treat others in front of others, and make a contract that turns their fantasies into reality...