The plain sister-in-law transformed! With the advice of her younger brother, she became a beautiful woman who turns heads. However, the younger brother has liked his sister-in-law since long ago... Before someone else steals her away, he musters up the courage to confess! He expresses his affection, but is rejected with the reason 'because we are siblings.' The younger brother says, 'Even if I can't insert it, just rubbing together is fine...' It was supposed to be an agreement for only frottage, but of course, it wouldn't end there... Once started, it doesn't stop and happens over and over again... The sister-in-law gradually becomes attracted to her younger brother as well.
