Both involves supernatural power of the main roles from each drama whereby they can see through other people future incidents or what will happen to them. The difference is that in TY, OTY is able to see other people future incidents after touching their skin whereas in SL, SHY is able yo see other people future incidents after touching their clothees

All involves three siblings separated when they were young due to the death of their parent. They met later both have desire to get revenge

Both dramas involves two non-relatives twin women (rich woman and other is poor from each drama), of which the rich woman from each drama engaged to the son form rich family but for business purpose and not real love but later on due to different reasons the poor one forced to be married to those chaebol sons and replaced the rich ones. In bride of century JYK didn't want to be married by CKJ so NDR replaced her. In mask, due to the coma happened to SEH and killed by her in-law, she was replaced by BJS. Both those sons from each drama had no feelings to these poor women in first place but falling for them later.