In 2015, Takahito Tsutsumitani was tasked with writing a review for a literary magazine on a book titled, “Jibun de Tsukureru 200-nen Kakeizu.” It was a how-to book on creating your own family tree, a pursuit that had become a bit of a fad thanks to the popularity of the NHK documentary series, “Family History,” which explored the ancestral roots of various celebrities — similar to the PBS series “Finding Your Roots” in the United States.

As a writer, Tsutsumitani specializes in topics relating to childhood education. He reviewed the book with the intention of using its suggested guidelines to trace his own lineage along with his 8-year-old son, a journey back in time that he hoped would become a memorable experience for both of them.

“At that point, I was only aware of where my father came from — Kyoto,” says Tsutsumitani, now 46. “But as I began gathering koseki, a whole new, unknown world opened up before us.”