TOSNET Corp. engages in the provision of security services. It operates through the following segments: Security Business, Building Maintenance Business, Mailing Service Business, and Power Supply Business. The Security Business segment includes transportation, facility, and train guard security services. The Building Maintenance Business segment handles the building maintenance and cleaning services. The Mailing Service Business segment manages the mail shipping agency; and sample and promotional item packing and shipping agency business. The Power Supply Business segment provides power supply by demand. The company was founded on March 30, 1977 and is headquartered in Sendai, Japan.