Toyota Motor and Kawasaki Aircraft (joint venture)
Revenue · FYE Mar 2026
$32.4B (¥5.12tn)
Net profit · FYE Mar 2026
$1.1B (¥172bn)
Aisin: long-term performance & turning pointsSales (revenue) and profit-margin ratio
Sales (¥ bn)Net margin (%)
1943From wartime aircraft to auto parts
Revenue (¥ bn, bars) · net margin (%, line)
Source: securities reports
1943Tokai Aircraft founded by Toyota Motor and Kawasaki Aircraft
1949Re-founded as Aichi Kogyo Co., Ltd. under the rehabilitation law
1952Listed on the Nagoya Stock Exchange
1961Begins manufacturing automatic transmissions
Aisin’s two roots both begin in the wartime aircraft industry. In 1943 Toyota Motor and Kawasaki Aircraft jointly set up Tokai Aircraft Co. to make aircraft parts in the last years of the Pacific War; its work on aero-engines lasted only until Japan’s defeat. The postwar ban on aircraft manufacture and the collapse of military demand stripped the firm of its business overnight, and through 1947–48 it converted to sewing machines and automobile parts, re-founding in June 1949 — under the corporate rehabilitation law — as Aichi Kogyo Co., Ltd. The origin of a Toyota-group parts maker thus lay not in a chosen enterprise but in the forced rebuilding of a defeated aircraft company.
Aichi Kogyo listed on the Nagoya Stock Exchange in 1952 and rebuilt on two legs — replacement auto parts and sewing machines — adding die-casting as a third pillar in 1953. In 1961 it began manufacturing automatic transmissions, the seed of what would become its defining business, and reached the first section of the Nagoya exchange that October.
Aisin’s other root was likewise born of the war. Shinkawa Kogyo, founded in 1945 inside Tokai Aircraft’s Kariya plant at the instigation of Toyota’s Kiichiro Toyoda, turned to civilian demand at the surrender and grew, as a direct Toyota-group supplier, into a maker of clutches and body parts. The two sibling companies — one strong in transmissions and brakes, the other in clutches and bodies — were being readied, though neither yet knew it, for a union.
1969Aisin Warner founded — a fifty-fifty JV with Borg-Warner
1970Listed on the Tokyo and Osaka exchanges; Aisin U.S.A. established
In August 1965 Aichi Kogyo absorbed its sibling Shinkawa Kogyo and took the name Aisin Seiki — Ai from Aichi and Shin from Shinkawa, so that neither name was lost. Eiji Toyoda, then a Toyota Motor vice-president, had floated the idea in 1961; the Toyota group let it mature for four years before the deal was sealed at the end of 1964. Combining two roughly equal makers of drivetrain and body components into a single firm was meant to harden the group’s core parts supplier.
The transmission business at the company’s heart carried a problem: the Warner-type automatic transmission that Toyota’s cars used rested on Borg-Warner’s basic patent, and Aisin could not develop it freely. Rather than fight, Aisin Seiki and Toyota Motor negotiated with the patent holder itself, and in 1969 the two sides set up the fifty-fifty Aisin Warner (renamed Aisin AW in 1988) in Kariya. The venture brought the AT technology in-house and grew into a business that held top-tier global share in automatic transmissions for the next half-century.
In 1970 the enlarged group reached the first sections of the Tokyo and Osaka stock exchanges and opened its first American company — the beginnings of a supply network that would follow Toyota abroad.
1981Global expansion and a Toyota-group parts group
Revenue (¥ bn, bars) · net margin (%, line)
Source: securities reports
FY1981 · unconsolidated
Revenue$1.0B
Net income$33M
Net margin3.2%
→
FY2010 · unconsolidated
Revenue$23.4B
Net income$189M
Net margin0.8%
1988North American operations split into manufacturing and sales arms
1991Aisin AI spun off for the manual-transmission business
2001Advics founded with Denso, Sumitomo Electric and Toyota
2010Kariya brake plant transferred to Advics
Through the 1980s and 1990s Aisin built out North America in step with Toyota’s own move to make cars there. It separated manufacturing from sales in 1988, re-consolidated them into a single American holding structure by 2001, and localized casting and automatic-transmission production along the way — the textbook pattern of a Toyota-group supplier following its customer overseas.
At home the group organized itself function by function. Manual transmissions were spun into Aisin AI in 1991, precision parts into a dedicated company in 1992, and casting had long sat in Aisin Takaoka — a lattice of specialist affiliates arrayed around the parent, Aisin AW and the rest.
The most consequential move was to pool brakes. In 2001 Aisin joined Denso, Sumitomo Electric and Toyota to found Advics, and by 2010 it had transferred its Kariya brake plant into the venture. It was one piece of a wider rationalization in which the major Toyota-group suppliers — Denso, Aisin, Toyota Industries and the others — traded and concentrated whole product lines among themselves.
2016Shiroki Kogyo (now Aisin Shiroki) made a wholly owned subsidiary
2021Absorbs Aisin AW; renamed Aisin Corporation
2025Absorbs Aisin Chemical, consolidating the group further
The recovery after the 2008 crash carried Aisin’s revenue to new highs through the 2010s, and the company moved to IFRS reporting. It also filled out its portfolio, taking full control of body-frame maker Shiroki Kogyo in 2016 and piston maker Art Metal in 2017, so that transmissions, body mechanisms, brakes, pistons and casting all sat within one group.
In April 2021 Aisin Seiki absorbed Aisin AW and renamed itself simply Aisin, folding the twin pillars built in 1965 and 1969 back into one. The logic was electric. An automatic transmission is a part an EV does not need, so the accelerating shift to electric vehicles cuts directly into what had long been the group’s earnings engine; unifying the company and the brand was a way to steer an AT-dependent structure toward electric drive — and to decide faster under one management.
Under Moritaka Yoshida, a career insider from Toyota Motor who became president in 2020, Aisin is investing in the next-generation ground — electric drive units (eAxle), electrified and self-driving components — while managing the measured wind-down of the AT business, and it absorbed Aisin Chemical in 2025. Eighty years after its 1949 re-founding as Aichi Kogyo, the company’s central question is whether it can re-bridge the assets of the transmission age to the electric one fast enough, carried on the steadiness of Toyota’s global sales.
The turning points, read in full: what was at stake, what was chosen and what the revenue did around it. The complete sourced record of each — background, options weighed, outcome — is in the Japanese edition, linked under every decision.
Revenue (¥ bn) · net margin % · around FY1965
Key decision · 1965
Merging Aichi Kogyo and Shinkawa Kogyo to form Aisin Seiki (1965)
Parity as the point of entry
The heart of this merger is that it was designed not as an absorption with a winner and a loser but as a union of equals. On paper Aichi Kogyo absorbed Shinkawa Kogyo, yet the new name took one character from each of the two firms and erased neither. The care taken — four years of maturing from Eiji Toyoda’s first proposal — suggests how well the Toyota group understood that a merger without genuine reconciliation, however favourable its terms, fails to take root. The character of this union lies in its refusal to hurry, in waiting for the fruit to ripen.
The birth of Aisin Seiki in 1965 became the foundation for the decisions that followed. Four years later, in 1969, the company obtained its automatic-transmission business through the joint venture with Borg-Warner, raising the twin pillars of the parent and its AT subsidiary. And half a century on, in 2021, those two pillars folded back into one in the reorganization for the EV era, and the corporate name was unified simply as Aisin. The 1965 naming that bound two sibling companies together by keeping one character from each became, more than fifty years later, the banner of the whole group — an illustration of how long an idea of parity at the point of entry can go on shaping the very form of a company.
Settling the AT patent problem with a fifty-fifty Borg-Warner joint venture (1967)
An entry that chose continuity over control
The heart of this decision is that Aisin sidestepped a fight over intellectual property and instead joined hands with the very holder of the patents. With the basic patent resting in Borg-Warner, winning a lawsuit was uncertain, and even a victory would have cost time and trust. Aisin Seiki and Toyota Motor chose not the outcome of a battle but a sure path into volume production for the coming age of the automatic transmission, turning the counterparty into an ally through the parity of a fifty-fifty split. That they pressed for a majority stake for two and a half years before settling on an even one can be read as valuing continuity over control.
As it turned out, the Aisin AW that this venture created grew into an AT company larger than the parent itself and underpinned the group’s earnings for decades. Ironically, the greater that success, the heavier the risk of carrying an AT mainstay into the EV era. The transmission business acquired from outside in 1969 was folded into the parent in 2021, and the two pillars became one again. The choice of a fifty-fifty joint venture at the outset did not foresee that integration half a century later, but it was among the decisions that shaped the form of Aisin for the longest time.
Integrating Aisin Seiki and Aisin AW under the single name Aisin (2019)
Undoing, under the parent’s name, a subsidiary that outgrew it
The heart of this integration is that the twin pillars produced by the two decisions of 1965 and 1969 were returned to one for the age of the EV. Folding the company that carried the half-century mainstay of automatic transmissions into a parent no smaller in scale, and unifying even the corporate name, can be read as an effort to harden — inside the company and out — the intent to re-engineer an AT-dependent earnings structure toward electric drive. The character of the reorganization shows in how it dissolved, under the parent’s name, the reversal by which the subsidiary had grown larger than the parent.
That said, making the name and the vessel one does not by itself guarantee competitiveness in electrification. How much of the technology and manufacturing accumulated in automatic transmissions can be carried across to electric drive units, and how the gap with front-runners such as Denso can be closed, are the questions left to management after the integration. Can the AT business — obtained half a century ago by buying into a patent through a joint venture — this time be re-bridged, by Aisin’s own hand, to the next mainstay? Whether the decision proves right cannot be fully judged until that path comes into view.
This is a condensed English edition. The full, source-by-source history — with the detailed narrative, financial tables, shareholders and executives — is maintained in Japanese: 日本語版(詳細)— Aisin full history in Japanese →