Madein Leymoon has a mermaid tail instead of legs, so he can't stand up. He is a merman prince in a kingdom that is under the sea. Madein can speak and understand human language, and his long silver hair will shine when illuminated by the moonlight. He was friendly and kind to other creatures under the sea. Madein likes moon, every night he will go to the water surface to look at the moon for a long time. Madein didn't like humans because he thinks humans are cruel due to his past trauma.