The grandmother of a 12-year-old Thai girl who was rescued in Japan as a victim of human trafficking rejected reports that her daughter forced the girl to work in a sex parlor in Tokyo.

“We’re landlocked. No beach. No waterfall,” says a sprightly woman in her 60s wearing pink lipstick. “But we have local wisdom. That’s our charm.” Auntie Ngiem is talking about mud. In the village of Ban Na Ton Chan in north-central Thailand ...