My cute little sister Haruna is an irreplaceable presence in my life. Whenever we're alone at home, she softly murmurs, "It's just the two of us now..." and gazes up at me with tender, inviting eyes. Her demeanor carries an alluring charm that quietly draws me in. One day, I was caught masturbating by accident—discovered by Haruna. In that moment, though slightly blushing, she naturally took my hand in hers and began helping me, as if it were the most natural thing in the world. Though I knew this was something a brother should never allow, my bond with Haruna continued to deepen. Her warmth and pure affection pulled me further into an undeniable desire.