"I'm Mahito. I'm just an ordinary high school boy." "But I have only one big problem." "It's that—my older brother is a shut-in and it really pisses me off." To that little brother thinking such things, I'll put him through gender swap and hypnotize him!!! By thoroughly hypnotizing him, he'll get used to his changing body and believe he's a little sister masturbator! And then, look. Who are you? "I'm Mai. A normal high school girl." "But I have one big problem" "And that's that..." "My brother is way too cool♡" "And it makes me get horny instantly♡" And now, your little sister masturbator that loves big brother is complete. Take good care of it for the rest of your life.