The South Korean melodramatic series "Thirty, Nine" tells the story of three friends, each of whom will turn forty in a year. They met in high school and have maintained their friendship throughout their lives. The main characters have learned to rely on each other in everything and work together to overcome any setbacks. They fall desperately in love, experience joy and sorrow, face losses and hardships, but most importantly, they share and support each other through everything that happens in their lives as they approach their fortieth birthday.