A 45-year-old unemployed man becomes the younger brother, brainwashing a serious female student until she ejaculates, completely controlling her. (SORA-595)

I'm outgoing, but I don't like studying. Lately, I've noticed boys keep staring at my chest. And my family isn't well-off… I don't want anything. I can't tell anyone about my desire to be a big sister or my longing for a little brother. It's strange, though; I've actually had a little brother for a long time, though we don't live together, we play together often. If I told my dad about this, he'd be furious. All I want is a little brother. I hate my dad for not even being allowed to have wishes and desires. Today I'm going to play with my little brother again. Because I'm the big sister.