The day her husband returned from a business trip, she was surprised when her husband's younger brother, Kiyotaka, suddenly showed up at the house. Eager to reunite with her husband after so long, his unexpected visit felt like an inconvenience—especially since she'd been feeling sexually frustrated lately. Still, worried about what might happen in her husband's absence, she politely welcomed him in. But that turned out to be a huge mistake. When she received a message from her husband saying he'd be late due to overtime, Kiyotaka suddenly made an unexpected proposal... and slowly, her emotions began to stir in response.