Living in an apartment, his younger brother and his wife needed help moving furniture, so the older brother came by one weekend to assist. Leading a life close to unemployed, he spent his days in quiet solitude—no social life, no romantic encounters, just a dull and aimless existence. That day, he joined in the moving work with his sister-in-law, hoping for a relaxed time. She smiled warmly and said, "Thank you so much, Onii-san, for helping out." Her plump, shapely hips subtly outlined the curve of her panties, drawing an inappropriate gaze from him. The story unfolds as the older brother becomes increasingly drawn to her irresistible charm.