By blending fiction with historical context and linking the past with the present, the tour quickly became popular among both French-speaking visitors and Chinese tourists. Many Chinese participants are touched by Le Guernic's efforts — as a foreigner — to highlight this important chapter of history that remains relatively unknown in the West.

"It's crucial to understand history," she said. "Only by learning from past tragedies can we avoid repeating them."

Le Guernic believes Shanghai still has many untold stories. "When I first arrived, everything was unfamiliar. After a few years, I thought I understood the city," she said. "But once I started researching for the tours, I realized how much more there is to uncover. The possibilities for discovery are endless."

One of her routes takes visitors through older neighborhoods — areas often ignored by mainstream tours. While these places may lack iconic landmarks and are gradually disappearing due to urban redevelopment, she believes they are key to understanding the city's transformation.

"For me, they represent not just Shanghai's past, but also its present and future," Le Guernic said. "Shanghai is constantly evolving, which gives me new stories to tell and new paths to explore."