From the Marusan-USA website:
"One of the toy companies from Japan whose products have endured over time is Marusan Co. Ltd. We know them by the mark of SAN in a circle as shown above. The Japanese word “Maru” means circle, thus the mark of SAN in a circle. But the word “San” also means three, which refers to the 3 founders of this company in 1947. Circles along with diamonds were popular logo marks for Japanese companies at that time as evidenced by the many marks we see within a circle or diamond.
The roots of this company began in 1923, when Naokichi Ishida founded Ishida Manufacturing, based in the Tawarachou, region of Asakusa, Tokyo. Their primary business was selling optical toys like toy binoculars, and telescopes. The Asakusa area of Tokyo was home to many toy companies.
In 1947 Naokichi Ishida’s sons, Haruyasu Ishida and his younger brother Minoru Ishida, and kinsman Yasuo Arai founded MARUSAN in the toy industry. Their business also was mainly selling tin toys and optical toys.
In 1950, the company was formally incorporated as MARUSAN SHOTEN LTD. “Shoten” means company or shop. At the time of incorporation, Haruyasu Ishida was President; Minoru Ishida was listed as Managing Director and Yasuo Arai was a Director.
Initially, their business was a wholesale sales business, but they eventually began to design and market their own toys.
In 1958, they introduced their first domestic plastic model kit, “Nautilus” submarine. The following year they sponsored their first Japanese TV program “Riku to Umi to Sora to” (land and sea and sky) focused on promoting plastic model kits into the Japanese market.
In 1960 President Haruyasu Ishida retired and Minoru Ishida was appointed president. The 1960s saw Marusan venture into die-cast miniature cars called “Toyo Ace” and plastic model kits of small airplanes.
The popularity of Godzilla movies inspired the1964 introduction of a battery operated remote control tin Godzilla and a remote control plastic model kit Godzilla.
1968 brought the unexpected bankruptcy of Marusan due to unique circumstances. However, the bankruptcy of Marusan eventually led to the establishment of two companies: In1969 Minoru Ishida, the president of Marusan Shoten Ltd. and Maruzan Co.,Ltd. rebuilt Marusan as Marusan Co., Ltd. At the same time, Koutaro Ishida, who was a director of these companies and a nephew of Minoru Ishida, built a new company named Bullmark along with two other ex-employees of Marusan, Saburo Ishizuki and Yutaka Shibata. Bullmark was a major producer of plastic kits and vinyl monster character toys until 1977 when it closed its doors.
Meanwhile Marusan was also very active in vinyl toys and created their own MARUSAN original monster series in 1970 and the “Ultraman Ace” series of mini toys in 1972. During the 1970s, Marusan eventually moved primarily into the OEM (Original Equipment Manufacture) business of producing toys and parts for others as opposed to producing original brand toys. In support of this strategy, they developed small elaborate gearboxes, which were used for many companies’ products, in 1981.
Marusan founder, Minour Ishida died on December 3, 1987 at the age of 72 and Aiko Ishida was appointed president. The following year manufacturing was begun in China.
Capitalizing on the nostalgia craze, Marusan returned to their own brand with reproductions of MARUSAN original monster series in 1997. Marusan now remains one of the old names in the Japanese toy industry."