Borh dramas deal with time travel and the attempts of the main lead to change the past/future. The decisions of the main lead are of great importance for the time-related plot and how small changes alter a person's course in life.

Both deal with time as their central theme and the struggle to find out the truth over a past event and how small changes can alter one's life in unexpected ways. Despite the fact that Reunited Worlds focuses on the Past, Tomorrow With You focuses on the future, the feeling they emit is similar