In this age of non-essential outings, Yuya, who runs a used car dealership, has a lot of meetings with people and has a hard time returning home. His wife Himari is not at home and can barely go out, and Yuya's stepchild Atsushi lives like a NEET, so she is fed up with the stressful stay-at-home lifestyle. One day, Yuya has to leave the house for a business trip to a neighboring prefecture, but... Due to a series of events, the stepmother and stepchild, who are close in age, end up in a relationship where they devour each other's bodies like animals, covered in the smell of sweat, semen, and love juices, for two months in a closed space called a shut-in room.