The novel “Please Look After Mom” by South Korean novelist Shin Kyung-sook has been released in the United States.

On the first day of its release on Wednesday, more than half of the first edition of the book was sold.

Knopf Doubleday Publishing Group, which is a top U.S. publishing company, printed 100-thousand first edition copies. Currently, the third edition of the book is being printed.

The New York Times has, in an unprecedented move, introduced the book three times, and Amazon-dot-com selected Shin’s piece as the “Best Book of the Month” in April.

More than one-point-seven million copies of the book about a mother and her family’s search for her after she goes missing in a crowded train station were sold in South Korea.