START-301 Seeing my plain, makeup-free older sister, whom I hadn’t spoken to in years, being forced by a flirtatious guy somehow left me feeling strangely betrayed, and I couldn’t stop getting aroused from the trauma. Miyajima Mei

Since I passed the entrance exam to a prestigious school, I had grown distant from my older sister. One night, when I invited Sugai, a classmate from the same school, to my home, he unexpectedly ran into my sister, who was there without makeup. That day, she was taken advantage of by Sugai, but she discovered a new sense of pleasure and began to blossom as a woman. I kept turning a blind eye as my sister was mistreated and gradually became involved with Sugai. Even today, I hear my sister’s moans through the wall and feel overwhelmed with desire.