ROYD-271 My older sister is plain and modest, but when she takes off her glasses, she becomes an incomparable beauty. When I couldn’t hold back and came on to her, she allowed me to go from intimate rubbing to direct intercourse, and I was able to have my first internal climax. Yuki Koiro

Koiro, a quiet and plain older sister-in-law. At home, she usually wears no makeup and glasses with a blank expression, but one morning she appears with just a little makeup on. Her younger brother, who has always cared about her, responds to these small changes, and little by little their relationship begins to shift. Unable to hold back any longer, he confesses that he has loved her for a long time. She refuses, saying they are siblings, but the two end up crossing boundaries and becoming physically intimate. Even after they think it is over, they cannot forget the excitement of that moment, and they eventually become fully involved. Once they begin, they cannot stop, and they continue to draw closer again and again.