Both are about the ML traveling back in time and trying to save the FL who he loved and who died in an accident.

Both are about one of the leads traveling back in time and trying to prevent the tragic death of the other lead. One is M/F and the other BL.

Both are about one of the leads traveling back in time multiple times due to an object connected to the other lead. They then try to change fate and save the life of the person they love who died tragically.

Both are about one of the leads traveling back in time multiple times due to an object connected to the other lead. They then try to change fate and save the life of the person they love who died tragically.

Both are love stories in which one of the leads is killed in an accident and the grief stricken other lead finds themselves traveling back in time multiple times to try to change fate and save them.

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Both have leads with an odd memory loss but are immune to or helped by the other lead. Both MLs have a scientific study or program that assists/keeps track of memory.

Both are mini dramas in which the FL has a long secret crush on the ML and follows him from high school to college, hoping to finally win his heart.

One is modern day and the other wuxia, but in both the FL is brought into the ML's house to impersonate his sister who she looks exactly alike. The ML either knows from the start or guesses very early that she isn't his sister, and the real sister in both dies in the first episode. Both MLs start out threatening to the FL but then soften and fall in love with her.

Both are Republican Era mini dramas in which the main couple were going to get married but then something horrible happened. The ML then becomes violent and keeps the FL as a slave in his mansion.

Both dramas have a similar feel and are about a detective partnered with a person with a special skill to catch a serial killer who has the same skill and controls their victims' minds in some way. One is fantasy, the other scientific, though.

Both dramas are quirky and feature a body swap due to a thunderstorm/lightning between a grandparent and their grandson.