A certain city in the northern Kanto region... Sumire, a pure housewife who has been married for three years, lives peacefully with her hard-working office worker husband. Sumire spent her days looking for a new home and previewed various properties in the city on the weekends, partly because the current rental apartment she signed for when she got married had become a bit cramped. The real estate agent's salesperson in charge of previewing the property had a bad feeling about such a beautiful married woman. One day, the salesman couldn't bear to persist in looking at the property, which was basically a closed room just for the two of them...!