Soccer player Hayasaki Ryoushirou returns home with a sports injury. When his four older sisters find little sister fetish material in his luggage, the only possibly therapy for his unacceptable (and non-existent) lolicon fetish is sex with his busty older sisters Yuri and Mio.
What's better than hypnotizing a girl into having sex with you? Realizing your hypnotization technique didn't work and that she did it with consent. Hah, who's the fool now!
Marina and Airi's single mother has recently gotten married. Their new step-dad seems like he'll make a loving father. Like a really, really loving father.