The ending of your next favorite kdrama is going to be sad, no, happy, no, make that hopeful. Well, says the director and the writer, maybe not. Let's just figure it out when we get there. Let's see what the audience wants.

While kdramas have more fans every day, partly because they are so interactive, the way they must be filmed to achieve that flexibility has been criticized. The criticism is aimed at the often-unrealistic pace of filming schedules.

Although filming may begin months in advance, most drama episodes are filmed and edited the same week they are shown. So, if you are seeing that drama, with subtitles, on a Thursday, that very episode may have been filmed in Seoul on a Monday. That's a filming schedule unheard of in other countries.

Part of the reason this happens is that kdramas are interactive. You start with a flexible storyline and then depending on viewer response, you can add episodes or change the course of the story. If viewers are not responding favorably, it's still possible to steer your story in another direction. Scripts are often written or rewritten while filming has already started. See the dramas "King of Dramas" and "Worlds Within" for an inside look at the way it works.

Actor Kwon Sang Woo, who recently appeared in "Queen of Ambition," was asked if he had a problem with the kdrama production system because of his comments about script changes during filming.

"I don't have a problem. If I did, I shouldn't be acting in this type of environment," said Kwon. "Korean dramas might be popular internationally because we film this way."

While flexibility may be part of the appeal, it makes for crazy schedules.

"I filmed all through the night until 6 o'clock this morning, and went home only to shower," said actress Yeom Jung Ah, when she was filming the drama "Royal Family."

The drama required several all-night shoots.

So if you see actors crying during a drama, it could just be due to missing a few nights' sleep. But sleep deprivation can have serious side effects. It can result in car accidents when crew and cast are driving home, as well as on-set injuries. Actors also suffer from exhaustion ironically forcing unscheduled delays in production.

Actor Lee Soon Jae who appeared in "My Princess" and the "High Kick" series, said that such conditions do not encourage actors to be in dramas.

One possible fix would be that production companies require scripts to be finished before shooting starts, so actors have time to study their lines and production can set up shots.

According to Kwon Sang Woo, the schedules are demanding but it's not good for an actor to be filming a long time in a high-tension environment either.

"It's equally exhausting to be filming a mini-series for half a year," said Kwon. "But if actors can act knowing the ending or the script, it would be good."

Or would it? Not if the end is going to be changed.