I visited my younger brother's house in Tokyo to see my lovely niece, Yui. Yui was very affectionate toward me and greeted me with great excitement the moment I arrived. Her smooth, white skin, the faintly visible clit, and her still-developing curves were so beautiful that they deeply stirred my emotions, drawing me to her irresistibly. One night, I found Yui in her room, engrossed in masturbating with a vibrator. Seeing this, I made up my mind to introduce her to inner pleasure. Gently guiding her with fingering, I then thrust my cock deep to hit her cervix, making Yui convulse intensely in powerful orgasm. Having discovered the ecstasy deep inside her pussy, Yui craved my cock passionately, and we repeated the act again and again until the day I left.