In 2002, Korean movie marketing was experimental. Some promoters cut 30-minute "teaser features" or summaries for TV broadcast or in-store displays (like on Samsung’s old "Movie Beam" service). It is possible a existed for cable TV in South Korea, but it has since been lost to time. The "31" might refer to a specific broadcast length.
presents a story of two brothers: Ho-jin, a carpenter, and Dae-jin, a car racer. Their lives are upended when they both fall into comas following separate car accidents on the same day. Plot Summary & Narrative Conflict The Transformation: Addicted 2002 Korean Movie 31
Here is a written piece exploring the film's narrative: In 2002, Korean movie marketing was experimental