The series stars Choo Young-woo, winner of the Baeksang Award for Best New Actor last year for his roles in 'The Tale of Lady Ok', 'The Trauma Code: Heroes on Call', and 'Head Over Heels', playing Demon 3375, a powerful being with centuries of existence. Lee Se-young, known for 'The Red Sleeve' and 'What Comes After Love', plays Deul-pan, a hotel employee. The combination of these talents promises a rich narrative and compelling performances, key elements for the success of the series. Netflix's choice of cast reinforces its commitment to emerging talent and the quality of Korean production.