Why "I Didn't Know" Doesn't Hold — How Far the Duty to Monitor Reaches

Not knowing can itself be the reason for liability. There are moments where "the report never reached me" simply will not do. How far does a director's duty to monitor reach? Drawing on two court decisions, this piece sets out its range and its limits.

01"I Didn't Know" Is No Excuse — The Two Faces of the Duty to Monitor

A director's job is not only to run their own portfolio. The duty to monitor the conduct of other directors and of employees, and the duty to monitor whether the internal controls the board itself built are in fact functioning — a director bears both. The first is monitoring of "people"; the second is monitoring of "the system."

That is why the plea "I didn't know about the material the floor put out" is not, on its own, a release from liability. Not knowing can itself be read as evidence that monitoring was neglected. Were the channels for reports to come up put in place, and were the reports that did come up actually being looked at? What is in question is not ignorance as a result, but the process that led to the ignorance.

02Supervisory Authority Rests on Each Member's Duty to Monitor

The board has the authority to supervise the directors' execution of their duties (Companies Act, Article 362(2)(ii)). But this authority does not belong to the board as a collective body alone. It becomes effective only when backed by the duty to monitor that each individual director bears. Attending the meeting and stamping the approval seal does not amount to having supervised.

What widened this range was the Daiwa Bank shareholder derivative suit (Osaka District Court, September 20, 2000). The judgment brought within a director's duty of care not only the duty to build internal controls but the duty to monitor how they operate. Building the system is not enough; fail to watch whether it is actually working and liability can follow. The damages awarded for that neglect ran to an enormous sum. If the duty to build that we saw in Vol. 6 is the "entrance," monitoring the operation is its "exit."

03The Principle of Trust — A Shield That Works Only When the System Is in Place

So must a director verify everything with their own eyes? No. There is the principle of trust. Where an appropriate system is in place and there are no concrete grounds for suspicion, a director may trust subordinates and fellow directors. Because an organization runs on a division of labor, it is impossible for one person to inspect everything.

This trust, however, is not unconditional. Where the system is defective, trust does not serve as a shield against liability. Saying "I believed in them" carries no weight when no reporting channel was designed and the checks were a mere formality. The same holds in materials review. Whether the review system is in place is the dividing line for "was it right to trust the floor?" The "interrogate the process" thinking of the duty of care we saw in Vol. 2 is at work here too.

04System and Foreseeability Draw the Boundary of Liability

What showed how the principle of trust actually works is the Supreme Court judgment of July 9, 2009 (the Japan System Technology case). In a case where an employee fabricated sales through an ingenious scheme hard to anticipate under ordinary circumstances, the Supreme Court denied the liability of directors who had put a commensurate risk-management system in place. The mere fact that the report had not come up did not, here, overturn that exoneration.

Two points decided the outcome. Whether a commensurate system had been put in place, and whether the wrongdoing could have been foreseen. Where a system exists and the wrongdoing was hard to foresee, liability is not imposed even if the result is bad. Conversely, where the system is lacking, or the harm was foreseeable yet left unaddressed, liability remains. Read alongside the Daiwa Bank case, two lines — the presence or absence of a system, and the foreseeability of the wrongdoing — come into view as the boundary of liability.

05To the Materials-Review Floor — The Presence of a System Changes the Weight of Liability

This structure of the duty to monitor connects directly to the practice of materials review. When an inappropriate material reaches the public, whether "the review department missed it" and "management didn't know" will suffice depends on whether the system was in place. If there is a review mechanism and a channel that escalates deviations upward is running, there is room for the principle of trust to operate. If there is not, a breach of the duty to monitor is squarely in question.

That is why review records are not the floor's clerical busywork. They are evidence that the system was actually functioning. Who, when, and on what grounds allowed or disallowed what. The thickness of that record decides whether, in a crisis, one can say "we did what we were supposed to do." In the next piece (Vol. 10), we dig further into how these review records become visible evidence of governance for the board. The reviewer stands at the front line where the duty to monitor descends to the floor.