I Am Legend (2010)

Legend and Sunny both have music in them. Also Ahjummas and their problems in life. The characters are kind of the same. Though Sunny has more quirky and funnier characters. Both are recommended.

Both these dramas involve music and the creation of a band.

Female-centric plots in both, with women at work and their sismances.
WWW working with search engines, IAmLegend with Music.

both have good female characters who have a second chance and build the life they wanted

Both have a story about a woman whose husband is unfaithful and whose stepmother mistreats her.

Both have a woman who is mistreated by the family they married into and have an un faithful husband.

same actress plays both female leads. both female leads have douche hat cheating husbands and get divorced. they also both lose a child and have the same fiery temper with some awesome fighting skills. both male leads are single fathers

Both of them has GIRL POWER!! Both has 4 Woman who experience harshness in life, joined together to make the most out of it. In "Legendary woman", they were joined mostly by their new hope which is their bakery, in "I am Legend", music is their denominator.

The friendship / sisterhood in both dramas is so strong that I wish I have one for myself. :)

Both about 'ajumma's who had mistake marriages because they got pregnant and decide to take their lives back. Both also have shallow cheating husbands.