When Singaporean Kristen Chng watched Chinese indie film Dear You with his father in Suzhou last month, he was reminded of his grandfather’s journey of sweat and hardship after leaving his ancestral village in Guangdong province with little to his name. There wasn’t a dry eye in the room, he said, as cinema-goers followed the story of a man uncovering his family’s past by tracing remittance letters sent home from Thailand. “My grandfather moved to Singapore in his teens and had a habit of...