In the post-apocalyptic world, new races are emerging as remnants of the old world. These new races in the new world possess various appearances but are capable of interbreeding. However, due to the strong dominance of paternal genes, maternal genes are gradually lost through generations. Therefore, each race forcibly impregnates females of other races in order to gain an advantage and ensure their survival. Defeated females are captured and used as tools for breeding within the opposing race. Weak races fade into history, leaving only the strong ones behind. Killing is not helpful, so each race competes through sexual combat. Snow tiger : Prefers to dominate opponents with superior combat skills and engage in forced sexual intercourse. Rat: Compensates for its relatively small stature with intelligence and weaponry. White-Eared Rabbit: Prefers wrestling based on excellent physical abilities. Brown-Eared Rabbit: Utilizes its massive physique to overpower opponents with sheer strength.