- Sumida Ward Official Website
- "VISIT SUMIDA" Tourism Office
- Sumida 3M (Museum, Manufacturing Shop, Meister)
Seiko Holdings Group
- Seiko Holdings Corporation
Consolidated management for each affiliated company within the Group
- SEIKO WATCH CORPORATION
Planning for watches and other products and domestic and overseas sales
- Seiko Instruments Inc.
Development, manufacturing and sales of watches, precision components and machine tools, electronic components, communication products and solutions, printers, measurement and analysis instruments
- SEIKO PRECISION INC.
Manufacturing/sales for electronic devices, shutters for cameras and peripherals, system integration, information equipment, system clocks and production equipment
- SEIKO NPC CORPORATION
Design, development and marketing of integrated circuits (ICs)
- SEIKO CLOCK INC.
Development, manufacturing and sales of clocks (table clocks, wall clocks, alarm clocks)
- SEIKOOPTICAL PRODUCTS CO., LTD.
Wholesale marketing of lenses and frames for glasses along with other optical-related products
- WAKO Co., Ltd.
Sales of watches, jewelry, accessories, interior supplies, art goods and crafts, glasses and foodstuffs
- SEIKO TIME SYSTEMS INC.
Manufacturing, sales and incidental installation work for system clocks, varied information display equipment and sports timing equipment, as well as timing and measurement services for various sports events