SAKURA Law Office is pleased to announce that an article by our attorney Naoki Kanayama, “Revisiting the Theory of Assistants in Contract Formation — (3, Final) Simultaneous Litigation Across Japan!”, has been published in the “Perspectives of Scholars” section of Consumer Law News No. 148 (July 2026).

Naoki Kanayama has long been engaged in research and education in civil law as Professor Emeritus of Keio University and also served as Director of the Maison du Japon at the Cité internationale universitaire de Paris. He is currently engaged in legal practice as an attorney. This article is the final installment in a series in which Mr. Kanayama reflects on the “theory of assistants in contract formation,” a subject he has studied for many years. After examining developments in French civil law concerning the interdependence of contracts, the article considers, from the perspectives of both a scholar and a legal practitioner, how the theory of assistants in contract formation can be applied to the actual relief of victims of fraud.

In the first part of the article, Mr. Kanayama discusses the 2016 reform of French contract law by ordonnance, which introduced provisions concerning the duty to negotiate in good faith, the duty to provide information, and changes in circumstances. He then examines Article 1186 of the French Civil Code, which governs legal relationships where multiple contracts are interconnected for the purpose of achieving a single transaction. Referring to decisions of the French Court of Cassation that formed the basis of the provision, as well as subsequent developments in case law, Mr. Kanayama evaluates the concept of contractual interdependence as an important legal development representing a departure from the individualistic classical conception of contract.

At the same time, the article clearly identifies the continuing limitations of the theory of contractual interdependence. Because the theory presupposes the existence of multiple contracts, it cannot be applied where a single contract is concluded as a result of factual conduct by a third party, such as improper solicitation. Furthermore, because the legal effect is limited to the lapse of the contract, even if, for example, a loan agreement ceases to have effect, the borrower may still remain subject to restitution or settlement obligations. Mr. Kanayama positions the “theory of assistants in contract formation,” which he himself has advocated, as a theory capable of overcoming these limitations.

One of the most significant aspects of the article is its clear commitment to connecting such theoretical analysis with the practical relief of victims through actual litigation.

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