49 Days (2011)

1) Both have a female protagonist whose soul leaves her body and has a 2nd chance at life by a reaper.
2) Both female leads discover secrets they didn't realize at the time of their deaths
3) Both show the horrid side of human nature that is revealed when the female protagonist is seeing it from a different perspective.

They have a similar concept, but in 49 Days, the female lead enters in another body. While IIWY has male & female switch bodies

According to tvN, this is a special episode explaining the complicated relationships of the characters as well as foreshadowing what’s to come “in order for viewers to be able to enjoy the remaining story with more fun and ease.”

According to tvN, this is a special episode explaining the complicated relationships of the characters as well as foreshadowing what’s to come “in order for viewers to be able to enjoy the remaining story with more fun and ease.”

Both females lead get into a car accident which bring her into a coma so her soul have a time limit to accomplish some missions to go back into her body otherwise she die.
All that with the help of a Reaper who forgot all is past life as a human but start to remember step by step...

Kyoko, a young woman with an unhindered spirit despite being physically bound to a wheelchair due to illness, and Shuji, a stylish and popular fashion magazine hairstylist, are brought together in a fateful traffic incident. Despite their confrontational meeting, they soon find themselves falling in love, with Shuji drawn to her courage and enthusiasm and Kyoko attracted to his ability to look beyond her physical limitations and into her heart. However, Kyoko's protective older brother and her worsening condition begin to test the bounds of their love for each other and threaten to end their beautiful life together.

Seon Woo receives calla every morning and wants to find out who the secret admirer is. One day, he goes to a nearby florist’s where he meets Ji Hee. He falls in love with her at first sight, thinking she is the one who is sending him flowers. Seon Woo asks Ji Hee to go on a date, and she agrees. He arrives at the rendezvous only to find that Ji Hee is held hostage and, to his horror, killed before his eyes.

Both of these series have a lot of similarities, for example both the female leads have a similar relationship with their husbands/ fiance. Because at first their husbands/ fiance cheated on them and both the female leads wanted revenge.

Story is so captivating!!! You keep screaming at your computer and yearning for more! Not to mention the eye candy!

College freshman Si Ying gets a part-time job at “Cafe. Waiting. Love” coffee shop, where she befriends Abusi, a tomboyish barista who can make any coffee the customers request, the beautiful and mysterious cafe owner, and Zeyu, the boy who always sits in the same spot in the cafe who seems to be very popular with girls and on whom Si Ying develops an instant crush.

Seung Hee, after losing his girlfriend in a tragic accident, left for 3 years. When he came back, he sought to make a film in a rural area. Someone caught his eye - Bok Shil, who looks exactly like his deceased girlfriend, Hye Soo. Seung Hee followed Bok Shil in order to get some answers and ended up falling for her.
Still the questions remain, is he attracted to Bok Shil because of the memories of his ex-girlfriend, or does he like Bok Shil for who she is? What happens when competitors come into the picture and families opposing their love?