Both the drama and movie include the son of the FML going back in time to help their mom and dad be together.
Both of them are about the mother's son from the future time traveling to the past to help his mom get together with his dad. Both of them also made their presence known by introducing themselves to the mom.
The difference is in I Belonged to Your World, the person the son wants to set up his mom with isn't his birth dad (he wants his mom to live a better life by not marrying his birth dad) and the son is already much older. In Please Be Married, the person the son wants to set up his mom with is his birth dad and the son is much younger.
The difference is in I Belonged to Your World, the person the son wants to set up his mom with isn't his birth dad (he wants his mom to live a better life by not marrying his birth dad) and the son is already much older. In Please Be Married, the person the son wants to set up his mom with is his birth dad and the son is much younger.
It is very similar since the child returns to the past to resolve conflicts between his future parents and prevent the death of one of them. In this ancient era she meets a man she will fall in love with. The difference between the two is that in « IBTYW » it is the mother who travels in time and she is approached by the son who comes from the future and will help her prevent the future drama, while in QJJD1998 it is the child who travels only to fix everything by himself.