Imouto no Tomodachi to Himitsu no Kankei

Saeki Sana, my younger sister’s friend, often comes over to our house to play. She’s a very shy girl, but we share a love for anime and manga. After talking a few times, we became friends. My sister isn’t interested, but we decided to go see a movie of a series we both like. After the movie, Sana confessed her feelings to me. I was so happy that I immediately said I’d go out with her, but… My sister had warned me beforehand not to make a move on Sana. What would our parents think about me dating Sana, who’s much younger than me…? “Um, would it be okay if I dated you, big brother, without telling Hikari or our parents?” And so, our secret relationship began.