Both dramas involve one or more of the main characters from a manga/webtoon world that teleports to the real-life world. These manga/webtoon characters get into a romantic relationship with the real-life character.

Both dramas are kind of about time-travel, and changing the past in order for the future to change. Both male leads have extreme patience, love and dedication to the female lead for a long period of time.

Both main male leads receive a heart transplant from the main female lead's former lover. Both main male leads soon develop some similar habits of the former lovers and eventually falls in love with the main female lead.