Every credited name in Parasite appears in another charting Korean title. In The Influencer, none of them do.

Join every Korean title that has reached a Netflix Top 10 to its recorded cast, and one question becomes answerable that no single title can answer: how much of this production’s cast turns up anywhere else?

Across the 297 productions with at least five recorded cast members, the median has 16.7% of its cast appearing in nothing else in the set. The spread around that median is the interesting part.

Every credited name in each of those appears in at least one other Korean title that charted. Now the other end:

What the two ends have in common

The 0% group is prestige feature film and flagship drama. The 100% end is reality television and youth casting. The Influencer is a competition show whose participants are influencers, not working screen actors, so of course none of them turn up in a Korean drama. My ID is Gangnam Beauty is a campus series that cast a lot of newcomers, and seventeen of its twenty-seven recorded names appear in nothing else here.

That is not a judgement about either. A production that draws entirely on the established pool and one that brings in twenty new faces are doing different jobs. What the join makes visible is that the difference is enormous and completely invisible from any one title.

Across the whole set, 654 of 1,355 people — 48.3% — appear in exactly one of these titles. Nearly half of everyone credited in Korean titles that reached a Netflix Top 10 did so once.

The limit that matters most here

Wikidata’s cast lists are incomplete, and that cuts directly against this measure. If a person was in five of these titles and Wikidata records one, we count them as a one-timer. So 48.3% is a ceiling on the true figure, not an estimate of it, and a production’s “only here” share is inflated by whatever its collaborators’ entries are missing.

The direction of the error is knowable even if the size is not: recording is fuller for well-known people, so the productions that look most self-contained are the ones cast with less-documented names — which is the same population the measure is trying to describe. We report the figure and the flaw together because separating them would make the number look better than it is.

Two smaller limits. “Appears in nothing else” means nothing else in this set — 906 Korean titles that reached a Netflix Top 10, not a career. And reality formats list participants under the same cast property as actors, which is why The Influencer sits where it does; that is Wikidata’s modelling, not a finding about casting.