Introverted Little Brother Steals His Social Sister

Iori's boyfriend is sweet and very handsome, but the sex isn't so good.... That's why she has trouble maintaining romantic relationships. And it's not as if she's physically insensitive, either... she has plenty of fun with her own vibrator. It's just that normal men aren't as good. Then one day, her shut-in little brother Aoi comes to her with a question. "I can't seem to get my girlfriend off. What do girls like?" Iori thought this was going to be a normal brother-sister talk...! *This is a romantic comedy about a clueless girl and her knowledgeable little brother. Contains no incest.