'Zaher,' possessed in a Western fantasy novel. In order to avoid getting entangled with the Demon King, 'Phelen', who will destroy the world in the future, he trains hard and plans to escape to a safe place. However, he encounters Phelen, who has not yet awakened as the Demon King, at the Academy Examination Center, and the two become roommates at the Academy. And at some point... they end up sharing not only a room but also a bed... The relationship between Zaher and Phelen, which continues precariously while maintaining the line of friendship. 'My friend... will become the Demon King?'