MIDE-823 A sister from my parent's remarriage, just one month older than me and always lording it over me. She comes to me every day for that. Mia Nanase.

My dad remarried, and I became a family with his new wife and her daughter. She's small and cute, like a little sister, but she's actually the same age as me? But as soon as she heard my zodiac sign, she suddenly changed! Knowing that I was born first, she started to look down on me. A constant top-down S-type older sister was born. Knowing that I'm a virgin, she started to look down on me while taking my virginity! Even in boring classes, she would jerk me off just to pass the time, even if there were people around! She even wanted to take the lead in positions, riding on top! She looks like a little sister but acts like an older sister, a top-down girl!