kookiejamz

Both main male character avoids his girlfriend so she won't be sad when he dies. Both are very sad and emotional.

Main character abandons her fiance when she falls in love with one of her students.

In both, tthe husband/wife falls in love with the kind imposter while the real one tries to murder the imposter.

Both deal with the pure love story between the rich and poor who broke up because of their parents. They meet years later and still have feelings for each other.

Both series expand on one of the male roles who is in love with his older brother's girlfriend, but gets friendzoned.

Plot and main leads are very similar, except that in Devil Beside You the two leads are soon-to-be stepsiblings.

Main character had a crush on her childhood friend for the longest time. However, there was a girl he got involved with that he couldn't reject. Leading male's parent also abandoned him at a young age, but meet again years later.

In both, the main character had traveled through time and was forced to act as the lookalike imposter of the king from that period. He attempts to unify the kingdoms into one country.