At home in Boulder, Colorado, Shors kept an English translation of Stories to Enlighten the World, a collection of short stories compiled and edited by Feng Menglong during the Ming Dynasty.

During the two-year writing process, he consulted about six experts on Chinese culture and history, including a few from the University of Colorado and one from China.

Referring to Shors' efforts to get the details right, Jeremiah Jenne, a Chinese history teacher at IES Abroad in Beijing, says: "The research John did on material culture is really strong, like some of the descriptions of the clothing, weapons and food."

The book is titled Unbound because its heroine, Meng, has unbound feet and what Shors calls an "unbound spirit".

Women's empowerment is an important subject in the story. As Shors sees it, Chinese women in the Ming Dynasty pushed boundaries in very subtle ways, for instance, in writing good poetry and getting out of home to travel.

So, Shors wanted his heroine Meng to reflect the powerful roles women played in China's history.

"I think there's a concept in the West that historically women in Asia were powerless. I just don't think that's accurate," says Shors.

"I wanted to show women as they truly were, perhaps repressed but yet powerful in their own way."

Women of modern China perpetuate Shors' notion.

For his side business, Shors organizes annual trips for small groups of readers to the Asian settings of his books.

In a 2016 tour to China, five of the six tour guides in Shors' group of 10, were female.

"They were super strong. If I had a problem, I would just say, please fix this problem, and they would fix it," says Shors, smacking the back of his hand on his other palm.

Meanwhile, Shors is looking for opportunities for Unbound to be published in China.

And he doesn't expect there to be more criticism coming from Chinese readers than from other parts of the world.

"I think they'll understand that as an American, I've done my best," says Shors.

"The vast majority of the book is historically and culturally accurate."

Speaking about the book, Huang Jiakun, Shors' agent in China, says: "He has probably set an example for Chinese writers on how to tell China stories."

Huang, who also worked with Shors when the Chinese version of his fourth book The Wishing Trees was published in China in 2011, says she considers Unbound a "faithful, interesting and innovative approach" to Chinese traditional folk tales that will appeal to readers beyond China.