Both are supernatural/fantasy dramas with an immortal male lead who falls in love with a human girl. Both have epic bromances, as well!

Both are versions of Itazura na Kiss but though they follow the storyline, both don't feel like remakes at all.

Both are horror dramas that take place in a haunted, cursed hospital.

Both are dramas about a young man that endures many hardships and setbacks as he pursues his dreams, but always remains optimistic and never gives up.

Both dramas are about the main characters hiding thier identity and carrying out justice during a politically turbulent period in Korean history.