1965	Oct.	Established Shoden Corporatjon in Chiyodaku, Tokyo, started manufacuturing and selling power supply equipment for computer electronic communication units, and undertook the related installation and communication work.
1969	Jan.	Acquired the sole agent in Japan for the products in the lighting surge arresters division of Siemens AG of Germany
1970	Oct.	Developed the earthquake-proof engineering method for duct floor,raised floor, and installed it in the communication machine room of Tokyo Electric Power Co.
1971	Mar.	Developed an information transmission circuit switching device, and delivered NO.1 device to a financial agency.
	July	Qualified as a maker conforming to electlic power standard D-205 specified by the Electric Enterprise Federation being organized by electric power companies in Japan.
1975	Mar.	Built a flew company building (SC center) at the present site (Koto-ku, Tokyo), and started operation as the head office and Tokyo factory.
1984	Feb.	Received the "lnvention Grand Award" for U-MF type deep buried grounding method from The Japan Society for the Advancement of Invention.
1986	Apr.	Concluded a distributor agreement with Dynatech Corporation in USA for matrix switches.
		Concluded a distributor agreement with Nokia Data Communications of Finland for modems and TDM.
	May	Developed an SD type earthquake-proof system and delivered NO.1 unit to Chubu Electric Power Co.
1987	Sep.	Constructed a new building in Chiba city and started business operation as the techno center for engineering and manufacturing.
1989	Nov.	Received both Ohm Technical Award and Shibusawa Award for the development and diffusion of SD type earthquake-isolation device.
1991	Sep.	Delivered SD-2 floor earthquake-isolation system and new OA floor to new Tokyo metropolitan office building.
1995	July	Concluded a distributor agreement with Avaya Inc.(Lucent Technologies Inc).USA for digital PBX.
	Aug.	Constructed the Narita factory in Chiba pref, Katori gun, Yamada-Machi.
1998	Aug.	Corporation agreement with ERICO Lightning Technologies Pty Ltd. , Hobart, Australia.
2000	May.	Osaka Plant is constructed in Konohana-ku, Osaka.
	Oct.	Awarded the Good Design Award for the development of the Thunder Blocker SPR-TB-100BT-A1.
2004	Mar.	Built a new head office, SD Bldg. at Sumida-ku, Tokyo.
		SC Center was established making use of former head office.
2005	Apr.	Developed the SD-5 Type II Rack-Mounted Seismic Isolator.
2007	Jan.	Completed the 200kA Lightning Impulse Current Generator in the Techno Center's experiment wing.