Tsubaki's husband has a particular fetish: he wants to see her deeply loved wife having sex with another person—what's known as a cuckold fantasy. However, he absolutely cannot stand the thought of her being stolen by another man. So, he asked Akari, a lesbian friend of him from college, to sleep with his wife. At first, Tsubaki was hesitant, but she gradually became consumed by the pleasure, revealing a climax she had never seen before. The sight excited Tsubaki's husband intensely. But after that, Tsubaki's behavior became strange. She started meeting Akari behind her husband's back and eventually stopped listening to him. And so, the two women progressed into an unusual relationship...