Park Chanyeol is rich, successful and attractive, but he's not happy; he lives a lonely life. One day, his life becomes too painful to live. He ditches work and drops his cellphone; walking wherever his feet take him. He boards a train to a place he doesn't know or care about. When a cheerful, annoyingly talkative boy takes the seat next to him, he realizes that life

Kibum is synaesthesiac, which means his brain processes sounds as colours. Every sound he hears, each vibration that his ultra-sensitive ears pick up, makes him see light- flashes, ribbons, patterns, spots. His condition may sound beautiful, but Kibum would rather be blind- he would rather be deaf.