With his wife away on a trip, Shu expressed heartfelt gratitude to his sister-in-law Kaori, who had kindly cleaned his messy room and prepared dinner for him. Standing before him, Kaori smiled contentedly. But the words she spoke were not mere affection—they revealed her desire for Shu's body. Unaware of her true intentions, Shu happily agreed. The night spent with his sister-in-law took an unexpected turn.