Watch Sing in Love for Free: How to Stream the Movie Online at 123Movies. . Jin is a temporary elementary school teacher on his way to a permanent position when a traumatic event plunges him into a terrifying deep darkness. Three months later, a mysterious man named Kai provokes Jin's memories and feelings regarding the past experience through rapping. Why is Kai obsessed with Jin? How does Jin confront his own "darkness"? Conflicts and battles for men who have been deeply injured inspire healing. And does true love exist on the other side?