The Japanese government’s posters show the map of a blood-red North Korea blotting out the eyes of a Japanese teenager. They hint darkly that this country’s youth are at risk and urge Japanese to open their eyes to the threat from North Korea.

The posters were on prominent display at a rally this week to call attention to Japanese abducted by North Korea three decades ago and who, Japan says, are still held there.

The people who usually show up at such events — family members, their supporters, members of right-wing organizations — waited for a special first-time guest: Prime Minister Shinzo Abe. “We can never compromise on the abduction issue,” Mr. Abe told the crowd. “I swear that my administration will tackle this as its top priority.”