The issue of Korean women who were forced by Japan to serve at frontline military brothels during World War II has been one of the thorniest issues facing the Seoul-Tokyo relationship.

With many of them already having died, Seoul has raised pressure on Tokyo to take steps to explicitly apologize to them and offer legal compensation for their past suffering.

Last Thursday, two more Korean former sex slaves died, reducing the total number of surviving victims to 50.

The average age of the surviving victims stands at 88.8, which underscores the urgency of the issue. Seoul has long argued it is a matter of human rights that goes beyond the Korea-Japan bilateral relationship.