Hi! When I saw Love Set for the first time, I felt some kind of sexual tension during the short. And after discussing with some people we came to the conclusion that maybe the Tennis match between the two characters is not just that, it's a kind of fight between lovers. That is, the characters of Bae Doona and IU were in an intimate relationship and now the IU character does not want Doona to marry with her father. There are many clues during the short (IU eating plums, the looks of Bae Doona, even the sounds during the game, the gesture of Doona when she gives the ball to IU). It's just a theory, but after discussing it and seeing Love Set once again everything makes sense.