まともなのは僕ひとり！？朝、目を覚ますと、性の価値観がぶっ飛んだ世界だった件。 (2020)

Overview

Living in a family of five, I'm an ordinary family everywhere, rather harder than any other home. However, when I woke up in the morning, the whole family was naked and started having sex in front of me. My mother, sister, and sister continued to have sexual intercourse with my father, looking sideways at me, who can only be upset.