What Do Hee-Do's Vacillating Reactions to Mentions of Yi-Jin Mean?
In episode four, present-day Hee-Do's mother mentions seeing Yi-Jin a month prior. Hee-Do looks somewhat distressed about this, which may indicate she still cares about Yi-Jin or that they didn't end on the best terms. Some fans are interpreting this as an indication they parted ways long ago on bad terms (otherwise, mentioning seeing Yi-Jin a month ago wouldn't have caused Hee-Do's expression to darken). But Hee-Do has a happy disposition when looking at the old photos of her friends (including Yi-Jin), so it could also suggest her expression darkens because of something else.
Later, in episode 10, Min-Chae mentions the trip Hee-Do went on with her high school friends, and Hee-Do says she doesn't remember the trip at all — despite expressing that she hoped the trip would last forever while they were on it. This, again, brings into question what type of lingering feelings Hee-Do has for Yi-Jin. While the fact that she's forgotten about a seemingly meaningful experience with Yi-Jin could suggest they didn't end up together and he's not Min-Chae's father, it could also mean that they did end up together and simply had 15 additional years of memories together that replaced their first trip to the beach together.
