While tending to business matters, he also devoted himself to scholarship, enrolling in the Kaitokudo, the well-known private school established in Osaka for the education of townsmen, studying Confucianism under its directors, Nakai Chikuzan and his brother Nakai Riken. Later he took up the study of Western astronomy and calendrical matters under Asada Goryu, taking a deep interest in matters pertaining to the technology and culture of the West, known at this time as Dutch learning. With the wealth at his disposal, he built up a large collection of books pertaining to astronomy, geography, and history, as well as books and articles imported from the West.
In 1760, at the age of twelve, he became heir to his uncle Masuya Kyubei, who operated a branch store for the wealthy Osaka merchant Masuya Heiemon. On reaching the age of adulthood in 1764, he abandoned his childhood name Sogoro and took the name Kyubei the Fourth. From 1772 on, he acted as guardian to the head of the Masuya establishment, who was still a young boy, overcoming various financial difficulties and improving the fortunes of the business. In time, by carrying on astute dealings with the Date family, lords of the fief of Sendai, and other prominent daimyo, he was able to reap large profits and to establish the Masuya as one of the largest and most powerful merchant houses of Osaka.
Around 1804 his sight began to fail, and in time he went blind, but he continued at his scholarly endeavors.
In 1820, at the age of seventy-two, he completed a major work in twelve chapters entitled Time no shiro, which deals with a wide range of subjects such as astronomy, geography, history, and economics and is noted for its critical spirit and highly rational and scientific approach. He also produced other works such as the Taichiben, which treats questions relating to prices, particularly the price of rice, leaving behind him a reputation as one of the most outstanding townsman scholars in Osaka history.