When my older brother jokingly said, "Hey, teach Takashi some judo, will you?" my life changed in an instant. From that moment on, my relationship with Mio, my brother's wife, began to twist and distort. As I struggled to improve for the summer judo tournament, my progress stalled. Then my brother returned from overseas, bringing Mio with him. A former third-degree black belt in judo, she started personally training me at my brother's house, where I moved in to focus on practice. During training, Mio's body constantly brushed against my groin, stirring intense arousal each time. These daily sessions slowly began to unravel my emotions, pulling me into forbidden desire.