In a small corner of Fukushima, an aging survivor of one of Japan’s most secretive World War II projects — sending balloon bombs over the Pacific to the U.S. — has finally decided to share his story, as part of a special exhibition.

Toshimizu Ishii, 96, has spent decades carrying the weight of memories he never wanted to revisit. But now, 80 years after the first balloons were launched toward the U.S., he feels a deep sense of urgency.

"If I don’t speak up now, the story will be lost," he said.