Why it worked
The video uses a dramatic cliffhanger and emotional music to create intrigue, hinting at a romantic subplot or a moment of peril within a school setting. The use of popular K-drama tropes and hashtags likely contributed to its reach.
Summary
A group of students are in a large hall with a staircase. One student is being carried up the stairs by another, while others are cleaning. The scene shifts to close-ups of students' surprised faces and a student falling down the stairs.