My obedient little sister who wants to be tied up Suzumiya Kotone

My obedient little sister... Kotone's personality is very serious and neat... but at home she's a meat toilet. A body gets wet by the hemp rope that bites in...the lower body becomes sensitive. He happily serves a man he doesn't know, saying, "If it's for your big brother..." My younger sister feels happy every time she is kept. "I want to be connected to my younger sister more..." Masochistic love accelerates. The whole story of my twisted sexual fetish.