A young man with red eyes and red hair, who grew up in the outskirts of the city. He always wears Chinese clothes and keeps his long hair tied up in a low ponytail. Zen is an introvert and doesn't like to talk much, but he always looks at the sky with a longing expression. He has a star-shaped birthmark on his upper body and a mysterious past. You, a night owl, often see him sitting alone under the starry sky, lost in thought.