Waka and Miyu have been best friends since their school days, and the two married couples remain close. Waka struggles to conceive and grows increasingly dissatisfied with sex. When Miyu suggests an AI compatibility test, the four jokingly try spouse swapping, supposedly only watching one another through cameras. Once Miyu’s husband forces himself on Waka, however, each person’s hidden tastes emerge and the group spirals into abandoned sex.