It follows the curious teenage sisters Yui and Rina as they participate in a "sex education" experiment with their older stepbrother Ken in a quiet suburban home. In a series of mind-boggling lessons, what begins as innocent questions turns into a taboo corruption tutorial. The girls' virgin bodies are claimed. This uncensored gem is a hardcore feast for fans of sibling seduction, coercion, and family debauchery because it has big tits bouncing, sloppy blowjobs, anal exploration, and a lot of creampies.