Directors of Japanese corporations (kabushiki kaisha) stand in a fiduciary relationship with their company. This relationship imposes several key duties, paramount among them being the duty of loyalty (忠実義務 - chūjitsu gimu) and the duty of care (善管注意義務 - zenkan chūi gimu). A specific and critical manifestation of these broader

The principle of separate corporate personality and the attendant limited liability of shareholders are fundamental tenets of company law in Japan, as they are in many other jurisdictions. A corporation, once duly established, is recognized as a legal entity distinct from its shareholders, possessing its own rights and obligations. Consequently,

The integrity of the patent system hinges on granting exclusive rights to those genuinely entitled to them – typically the true inventor or their rightful successor. However, situations arise where a patent application is filed, or a patent is obtained, by an individual or entity that did not invent the subject

When a patent is infringed, one of the primary remedies sought by the patentee is monetary compensation for the harm suffered. In Japan, the calculation of damages in patent infringement cases is fundamentally based on general tort principles under the Civil Code, but it is significantly supplemented by specific provisions

Patent licensing is a cornerstone of technology commercialization and strategic intellectual property management. It allows patent owners to generate revenue, expand market reach, and foster innovation by permitting others to use their patented technology. In Japan, like in other major jurisdictions, patent licenses are primarily categorized into exclusive and non-exclusive

Joint ownership of intellectual property, including patents, is a common outcome of collaborative research, joint ventures, or through the assignment or inheritance of patent rights. However, the legal framework governing the rights and obligations of patent co-owners can differ significantly from one country to another. These differences have profound implications

In today's innovation-driven economy, a significant portion of technological advancements arises from the research and development efforts within corporations, carried out by their employees. The question of who owns these employee-generated inventions and how inventors should be compensated is a critical aspect of intellectual property law and employment

The journey to obtaining a patent begins with a fundamental question: does the subject matter at hand qualify as a patentable "invention"? This threshold determination is critical, as only true inventions are eligible for the exclusive rights that a patent confers. In Japan, the Patent Act provides a

When a patent infringement lawsuit is initiated, the primary focus is often on whether the accused product or process falls within the scope of the patent claims. However, an equally critical aspect of patent litigation in Japan, as in many other jurisdictions, is the ability of the defendant to challenge

Patent rights grant exclusive control over an invention for a limited period, a system designed to incentivize innovation. However, an overly broad application of these rights could stifle further technological development and scientific inquiry. To prevent this, most patent systems incorporate an "experimental use exception," allowing certain types

In the competitive landscape of innovation, businesses often independently develop technologies that, unbeknownst to them, are later patented by another party. Japan's patent system, which operates on a "first-to-file" principle, generally grants patent rights to the first person to file an application for an invention, regardless

The patent exhaustion doctrine, often known as the "first sale doctrine," is a fundamental principle in patent law that limits the extent to which a patentee can control a patented article after an authorized sale. Once a patented product is sold by the patentee or with their consent,

Patent law typically addresses direct infringement, where an entity makes, uses, sells, or imports a patented invention without authorization. However, modern commerce often involves complex supply chains and multiple actors. Recognizing this, many legal systems, including those of Japan and the United States, have established provisions for "indirect infringement.

In the realm of patent enforcement, the precise wording of patent claims defines the boundaries of a patentee's exclusive rights. However, strict adherence to literal claim language can sometimes allow infringers to make minor, insubstantial changes to a patented invention and thereby evade liability, undermining the patent system&

Interpreting the scope of patent claims is a cornerstone of patent law, dictating the breadth of protection afforded to an invention and forming the basis for determining infringement. While the ultimate goal of claim construction is similar across jurisdictions – to ascertain the meaning and scope of the claims – the methodologies

In the landscape of Japanese commercial and financial transactions, particularly involving parent companies and their subsidiaries or joint venture partners, instruments known as "comfort letters" (経営指導念書, keiei shidō nensho) or similar "letters of support" frequently appear. These documents are often provided by a supporting entity (e.

When an individual or entity acts as a guarantor (保証人, hoshō'nin) in Japan by securing the obligations of a principal debtor (主たる債務者, shu-taru saimusha), they undertake a significant potential liability. If the principal debtor defaults and the guarantor is called upon to fulfill the debt to the creditor,

When an individual in Japan is asked to guarantee debts incurred by a principal debtor for business purposes, they often face a significant information imbalance. The principal debtor, typically a business entity or an entrepreneur, possesses detailed knowledge of their financial situation and the risks associated with the business, while

In Japan, as in many economies, small and medium-sized enterprises (SMEs) often rely on personal guarantees from individuals to secure financing or other business-related obligations. Historically, this practice led to numerous instances where individuals—particularly those with personal ties to business owners but limited direct involvement or understanding of the

Revolving guarantees, known in Japanese as ne-hoshō (根保証), are a common feature in ongoing commercial relationships. Unlike a guarantee for a single, specific debt, a revolving guarantee covers a series of unspecified future obligations that may arise within a defined scope of continuous transactions (e.g., under a line of

In Japan, a guarantee agreement (保証契約, hoshō keiyaku), by which one party (the guarantor) undertakes to secure an obligation owed by a principal debtor to a creditor, is not a casual affair. Recognizing the significant, often unilateral, burden placed upon guarantors, Japanese law imposes a strict formality requirement for these

Guarantee obligations (保証債務, hoshō saimu) are a cornerstone of secured transactions and credit enhancement in Japan. When a party (the guarantor) undertakes to secure the debt of another (the principal debtor) for the benefit of a creditor, a distinct legal relationship is formed. Understanding the fundamental nature and inherent characteristics

When a single debt that is capable of being divided—most commonly a monetary sum—is owed to several creditors, a fundamental question arises: how are the rights of these creditors structured? Can one creditor demand the entire amount, or is each entitled only to a specific portion? Under the

When a single, divisible debt is owed to multiple creditors, the default rule under Japanese law—similar to many other jurisdictions—is that of "divisible claims" (分割債権, bunkatsu saiken). In such cases, each creditor can typically only demand their respective share of the debt from the obligor. However,

When multiple parties are bound to perform a single obligation, Japanese law provides specific frameworks to govern their liabilities. While joint and several obligations (rentai saimu) are common for monetary debts, a distinct category exists for situations where the performance itself, due to its inherent characteristics, cannot be divided among