Full spoilers follow. Note that publicly available English-language documentation of this web drama is thin at the episode level, so this analysis covers the plot movements that are actually recorded rather than a scene-by-scene reconstruction.
The premise's real mechanism. Yoo Eun-sung is not simply a woman with a superpower; she is a failed trainee given the power to redirect other people's careers. That combination is the series' engine. Her flashes of the future are what let a rookie manager compete in an industry where she has no leverage, and the show's cruelty is that the gift only ever lets her serve someone else's debut, never her own.
The central crisis. S.O.U.L. begins on the verge of disbandment and is then hit with a plagiarism accusation, and the resulting public bashing — not a rival group, not a villainous executive — is the antagonist for much of the run. The group's fight is to regain popularity in the face of an accusation that the format of online opinion makes effectively unanswerable. This is why the eventual comeback reads as survival rather than justice: the record is never cleared, it is simply overtaken.
The romance. Eun-sung develops a romantic relationship with one of the group's members, which the series positions as structurally dangerous — in this industry, the relationship is the one liability her precognition cannot manage away, because it originates with her.
The finale ('Me Gustas Tu', episode 16). S.O.U.L.'s music climbs the charts. The comeback works. And the immediate consequence is a tightly packed schedule for every member. Eun-sung is proud of them — and then an event causes her to reevaluate her job as a Starlight manager. This is the hidden meaning the whole series has been building toward: the goal the audience has been rooting for turns out to be the trap. Winning does not release these people from the machine; it binds them to it more tightly. Every earlier episode of exhaustion and crisis reads differently once you see that the reward is more of the same at higher volume.
The unresolved vision. The series closes on ambiguity, and the specific detail viewers have never stopped arguing about is that Eun-sung does not appear to recognise certain figures in her final vision of the future. The implications are mutually exclusive and deliberately unadjudicated: either the future she has been reading all along is further off — and stranger — than she assumed, or the people in it are ones she has not yet met, meaning her story continues past the frame. Fans overwhelmingly read this as a hook for a second season. No second season was produced, which converts the hook into the ending. Whatever the writers intended, the effect is that the series terminates on an image of a future its protagonist cannot interpret — a fitting last statement from a show about a woman whose gift was always fragments and never explanations.