[5][6] Around the time the mokkan was inscribed, Nara would have been an ethnically diverse metropolitan area associated with the Silk Road and about to become Japan's capital city.

The book describes the arrival in Japan in 634 of several people from a place known in Japanese as Tokhārā (believed to be Tokharistan, which would have been part of the Sasanian Empire) and Dārā, a Persian man who worked for the emperor and returned to his homeland in 660.

This coincided with an economic boom in Japan which created a need for unskilled laborers, allowing migrant workers without the money to travel to the Western world to secure high-paying jobs and support their families in Iran.

[10] Airfare subsidized by Iran Air and a bilateral visa-exemption agreement which had been in place for decades allowed for relatively easy and affordable travel between the countries.

A number of workers had trouble finding work while their permits were in effect, however, and reported that Japanese employers intentionally waited until a worker's permit expired to offer them a job at a fraction of the prevailing wage; deportation was a possibility if they complained about unfair wages.

Some Iranians then became low-level yakuza (members of the Japanese mafia), selling illegal drugs and cell phones.

[14][15] In February 1979, the Iranian monarchy was collapsed by the revolution; nevertheless, the diplomatic relations with Japan have been inherited and the Embassy of Iran, Tokyo has continued to this day without any suspension.

[18] Money earned abroad contributed significantly to their social mobility; 57 percent of a sample of 120 returnees used their savings to start their own business and become self-employed after holding unskilled jobs working for others or as farmers before their migration.