Four years into her marriage, housewife Kyoka Tachibana was patiently waiting for her husband Yosuke's raise, living an ordinary and peaceful life. However, when Yosuke unilaterally prioritized a delivery for a client without approval, he was reprimanded by his boss, Sagawa, putting his promotion prospects in jeopardy. To resolve the situation, Sagawa presents Kyoka with a proposition—only once. This offer begins to shake Kyoka's resolve, gradually awakening intense carnal desires within her, ultimately leading her to make choices that pull her completely into a world of forbidden passion.