Between Two Worlds: How Did I Become My Great-Grandpa?

Period novel + travel between eras + making money and building a career + raising children to excel + a thriving family Yuan Lang, a modern man, transmigrates into the body of his great-grandfather Yuan Kang and can travel back and forth between the 1980s and the 21st century. The Yuan family is destitute in the 1980s, and his unreliable old grandpa is more trouble than he's worth. So Yuan Lang builds his fortune by moving goods between the two eras, while setting his unfilial forefathers straight and showing them how to become the richest people in the world!