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Aida Yasuaki studied under the mathematician Yasuyuki Okazaki in Yamagata from the age of 15 years. The city of Yamagata in which Aida was born and brought up was (and still is) situated in northern Honshu, Japan nearly 300 km north of present day Tokyo. In 1769, Aida went to Edo, which has been renamed Tokyo. There Aida worked for the shogunate of Tokugawa Ieharu. The shogunate was the government of the shogun, or hereditary military dictator, of Japan and this type of rule lasted from 1192 to 1867. The third shogunate in Japan was established in 1603 ruling from Edo. The shogunate was extremely powerful, controlling the emperor, controlling the religious establishments, administering the lands and forming foreign policy. Aida was employed by the shogunate as a civil engineer working on river control and irrigation systems around Edo. However, this was not the job that Aida aimed for since ever since he was young his aim had been to become the best mathematician in Japan. Also working for the same shogunate at this time was Teirei Kamiya, a mathematician who had been a pupil of Sadasuke Fujita. Aida would have liked to become a pupil of Fujita, for he was one of the leading mathematicians in Japan. Aida saw his friendship with Kamiya as means to be accepted by Fujita and asked Kamiya to arrange for him to be introduced to Fujita. Indeed Kamiya organised the necessary introductions but Aida was not accepted by Fujita. It appears that relations between Fujita and Aida may have been poor even before Kamiya arranged the introduction, although if that were the case it is unclear quite why Aida worked so hard to obtain the introduction. It was the custom of the time for mathematicians to donate tablets inscribed with mathematical problems to religious temples. These tablets represented offerings of scholarship to the gods. Aida had donated some tablets which contained errors and these had been spotted by Fujita. Perhaps Aida was unaware of these errors at the time he sought to become Fujita's pupil. Fujita had published a mathematical work Seiyo sampo in 1781 and in part his high reputation rested on this highly regarded text. Aida now decided to write a work based on the Seiyo sampo yet one which would criticise this work. It is not surprising that relations between Aida and Fujita would deteriorate further when Aida published Kaisei sampo, his critical revision of the Seiyo sampo. The private feud extended to include other mathematicians when Kamiya, who had lost face by arranging the failed introductions, attacked Aida's Kaisei sampo.