The short but impactful message from her homeroom teacher—"Go to sleep already."—left Ha-eun turning in for the night an hour or two earlier than usual. Whether it was due to the renowned effects of the hotel’s open-air bath or simply the carefree fun of spending the day with friends without worrying about acting, academics, or streaming, she couldn’t say for sure.

By 6 a.m., Ha-eun found herself wide awake.

“Breakfast probably hasn’t started yet… What should I do?”

Her mind was unusually clear for someone who had just woken up, and she felt refreshed rather than groggy. The other girls, …