41-year-old Ryuji Kurosaki was a former detective and now a detective, showing off his name reasoning every day and solving the client's problems. He is a strong smoker, a hard-boiled charm, and a longing existence of Shun Yagami, a junior of the detective agency. However, Ryuji also has some worries ... One day, I wake up and register with a dating agency in search of a lifelong companion and start marrying! With the support of Madoka Kido, an adviser, Ryuji, who is deep and does not understand the woman's heart, struggles ...!