When I first met filmmaker Eiji Han Shimizu two years ago, it was at a screening for his 2012 film “Happy,” an uplifting documentary that explores the roots of happiness around the world. After the credits rolled, he showed the audience a snippet of “True North,” his animated feature inspired by the true stories of North Korean prison camp survivors.

I remember thinking, “How did he go from exploring the source of happiness to depicting one of the darkest places in today’s world?” Shimizu’s film, which will have its Japan premiere at the Tokyo International Film Festival (TIFF) on Nov. 1, follows the harrowing journey of 9-year-old Yo-han and his family, who are taken from their home and imprisoned after the father is accused of a political crime. At the prison camp, they struggle to survive in unimaginably harsh conditions.

The answer to my question lies in Shimizu’s search for purpose.