While Papa and Mama are away on a hot spring trip with the local neighborhood association, the proactive younger sister Mai plays lewd pranks on her beloved older brother. In his room, kitchen, entrance hall, bedroom, bathroom, and more, she relentlessly goes at it all day long, having sex and making him ejaculate over and over again! "Brother, you're amazing! You can shoot out this much milk, so you can still go on, right?"
