period from 1960 through 1961. However, as word came back of difficult conditions in the North and with the 1965 normalization of Japan-South Korea relations, the popularity of repatriation to the North dropped sharply, though the trickle of returnees to the North continued as late as 1984. In total, 93,340 people migrated from Japan to North Korea under the repatriation programme; an estimated 6,000 were Japanese migrating with Korean spouses. Around one hundred such repatriates are believed to have later escaped from North Korea; the most famous is Kang Chol-Hwan, who published a book about his experience, The Aquariums of Pyongyang. One returnee who later defected back to Japan, known only by his Japanese pseudonym Kenki Aoyama, worked for North Korean intelligence as a spy in Beijing. The repatriations have been the subject of numerous creative works in Japan, due to the influence they had on the Zainichi Korean community; One documentary film about a family whose sons repatriated while the parents and daughter remained in Japan, Dear Pyongyang, won a special jury prize at the 2006 Sundance Film Festival. Some Zainichi Koreans have gone to South Korea to study or to settle. For example, author Lee Yangji studied at Seoul National University in the early 1980s. Korean organizations in Japan – Chongryon and Mindan Division between Chongryon and Mindan Out of the two Korean organizations in Japan, the pro-North Chongryon has been the more militant in terms of retaining Koreans' ethnic identity. Its policies included: Operation of about 60 ethnic Korean schools across Japan, initially partly funded by the North Korean government, in which lessons were conducted in Korean. They maintain a strong pro-North Korean ideology, which has sometimes come under criticism from pupils, parents, and the public alike. Discouraging its members from taking up Japanese citizenship. Discouraging its members from marrying Japanese. Chongryon-operated businesses and banks to provide the necessary jobs, services, and social networks for Zainichi Koreans outside mainstream society. Opposition to Zainichi Koreans' right to vote or participation in Japanese elections, which they saw as an unacceptable attempt at assimilation into Japanese society. A home-coming movement to North Korea in the late 1950s, which it hailed as a socialist "Paradise on Earth". Some 90,000 Zainichi Koreans and their Japanese spouses moved to the North before the migration eventually died down. Well into at least the 1970s, Chongryon was the dominant Zainichi group, and in some ways