Who Knows Whether It's Good or Bad (Korean title: 좋은지 나쁜지 누가 아는가) by Ryu Shiva has been read or recommended by 5 Korean celebrities, including Kang Haneul, Go Min-si, Chang Kiha. Below, each entry shows where they mentioned it and what they said.
In a GQ interview he called it a book he loves. After reading it twice he decided the essence of the book is its title, adding that if you really grasp the title you almost don't need to read it. (Source: GQ Korea)
Mentioned as a recent read with really good content. (Source: X)