Corporate History

The origin

After the end of the war, the founder, Kiyofumi Tanaka, established the company by leveraging the engine technologies he had cultivated at Nakajima Aircraft.(

(The company was originally named Tokyo Plant Kogyo Co., Ltd. at the time of its founding.)

In the early years, the company devoted itself to the research and development of various custom‑made test systems.With support from students in the University of Tokyo’s research laboratories, the company began manufacturing and selling Japan’s first soil testing machines.It also started manufacturing and selling a constant‑speed friction tester jointly developed with the Industrial Technology Agency.

This test system remains the basis of the current JIS standards (JIS D4311 and D4411).

Founding period

NS We developed the NS continuously variable transmission and manufactured fuel‑injection pump testers equipped with this unit.

We also began the development and sales of related products such as clamp‑type oil level gauges and index handles.

From the late 1950s, we studied advanced technologies in Germany and the United Kingdom, initiating the research and development of water dynamometers, which later became one of our core products.

The Emergence of the hydraulic Dynamometers and the Expansion of Our Business

The company changed its name from Tokyo Plant Kogyo Co., Ltd. to Tokyo Plant Co., Ltd.In 1964,

we delivered the first model of our water dynamometer to Komatsu and Hino Motors.

In 1969, our high‑speed water dynamometer was recognized at the Tokyo Invention Exhibition, receiving the Governor of Tokyo Award.This innovative technology led to the acquisition of numerous patents and utility

models both in Japan and overseas.Under an industrial promotion initiative advocated by the Ministry of Education, we supplied a wide range of internal‑combustion engine experimental systems—combining the Tanaka‑type water dynamometer and eddy‑current dynamometer—to technical high schools and various end users.

Received the Medal with Purple Ribbon for our Hydraulic dynamometer technology.

In 1972, our company achieved a significant milestone by successfully developing a hydraulic dynamometer utilizing a direct‑control method based on recirculating water.

This technological breakthrough earned our founder the Medal with Purple Ribbon, presented by the Prime Minister of Japan, Kakuei Tanaka, in recognition of outstanding contributions to the field of science and technology. Our innovations also began to be featured in technical publications related to engine engineering.

During the second‑generation leadership, the company began full‑scale overseas exports through trading companies.

The first President, Seishi Tanaka, stepped down due to health reasons, and Seifu Tanaka—then Director and General Manager of Sales—assumed the role as the second president.

Following this transition, the headquarters was relocated to Excel Heights, 4‑16‑9 kyonancho, Musashino, Tokyo. To further strengthen our international business, we began expanding into Southeast Asia and Eastern Europe through strategic trading partners.

During this period, we successfully developed and commercialized a portable type dynamometer, a compact version of the Tanaka’s hydraulic dynamometer.

During the second‑generation leadership, we strengthened its production capabilities.

April 1992：Constructed a new headquarters and factory at 515‑5 Miyazawa‑cho, Akishima City, Tokyo, further strengthening its production　　　　　　capacity and quality‑control framework.

November 1992：Using the portable water dynamometer, we developed and commercialized a wheel dynamometer, which was subsequently 　　　　　　delivered to racing shops.

Transition to the Third Generation Strengthening of Global Partnerships　

During the 2000s, we shifted from relying solely on trading companies to establishing overseas distributors across Korea, Thailand, Taiwan, and Hong Kong.

In 2005,we entered into a technical partnership with MAHA, the world’s No.1 chassis dynamometer manufacturer.

In 2009,Kiyohiro Tanaka became the company’s third President & CEO, further enhancing international collaboration, including a joint project with TYK for DPF performance evaluation.

Partnerships with Leading European Companies

In the 2010s, we diversified into automation, simulation tools, and advanced measurement systems through collaborations with European partners such as D2T (France).

Our powertrain engineering business plan was selected for a major subsidy by Japan’s Ministry of Economy, Trade and Industry.

In 2014, we established D2T JAPAN, marking a new chapter in our global technical expansion.

Expansion business domain

2015- Approved by the Tokyo Metropolitan Government for its Management Innovation Plan, recognizing our next-generation engineering initiatives.

2016- Formed a technical partnership with TECTOS (Austria) and launched sales of shafts, dampers, and drivetrain components.

2017- Signed a distributor agreement with FEV Japan, strengthening our European engineering collaboration.

2019- Established a satellite office in Osaka as our West Japan sales base.

2019- Chairman Seifu Tanaka retired after decades of leadership(He passed away on March 29, 2021, at the age of 78).

Expansion business domain

2020- Renamed our contract engine testing business to the Powertrain Engineering Division, marking a stronger commitment to advanced development and testing solutions.

2022- Established a dedicated hydrogen engine testing facility at the Fuji Technical Center in Shizuoka, becoming one of the few companies in Japan capable of such test.

2023- Launched the Motor Bench Business, expanding our test system portfolio to support electrification Opened the Fuji Technical Office in Shizuoka and the Kansai Technical Office in Osaka to increase customer coverage and engineering capacity.Approved as a full member of the Japan Internal Combustion Engine Federation (JICEF).
Participated in the second stage of the Ministry of the Environment’s national project.

Subsidiary in Africa

2024- Founded our subsidiary, Tokyo Plant Senegal SARL, in Senegal, West Africa.
As a new startup initiative, we began diversifying our business to address water-related challenges across the region.

Expansion business

2024- We participated in the establishment of Japan Hydro Co., Ltd.’s Hydrogen Engine R&D Center, which has now been successfully completed.

Expansion business

2025- Partnership with HIEN Aero Technologies We have formed a strategic partnership with HIEN Aero Technologies Co., Ltd. With a view toward the rapidly expanding global air mobility ecosystem, we are collaborating to develop and validate eVTOL aircraft and critical components, while building advanced testing environments.Together, we are launching comprehensive solutions that support next-generation aviation innovation.

事業領域のさらなる拡大とシミュレーション分野への参入

2026年4月：ENORISE SAS社とジョイントベンチャーとして、ENORISE Japan株式会社を設立。
シミュレーション、オートメーションシステム分野の強化。

Further expansion of our business domains and entry into the simulation field

April 2026：Established ENORISE Japan Co., Ltd. as a joint venture with ENORISE SAS, strengthening our capabilities in simulation and automation systems.