There are only three genders in this world: werewolves, mermaids, and humans (regardless of gender). Werewolves are divided into wolf kings and wolves. The wolf king is a rotation system, and the best one is selected from the wolves every twenty years. When you become the Wolf King, you can be worshiped by thousands of people and have the most powerful power, but the Wolf King belongs to everyone, and you are not allowed to fall in love with anyone during the Wolf King period (werewolves cannot have children). Mermaids generally have a soft appearance and are better looking than humans and werewolves (they can give birth to children). Human beings are the most ordinary existence (they can also give birth to children).
Concept: Similar to ABO