The regulation of seller’s warranty liability under the revised Japanese Civil Code

This paper examines the regulations on the seller’s liability for warranty under Japan’s revised Civil Code (Law of Obligations), which came into effect on April 1, 2020. The author’s motivation for exploring this topic stems not only from curiosity about the outcomes of the revision but also from a strong interest in the legislative techniques employed to simplify, integrate, and reorganize the substantial provisions on the seller’s liability for warranty into a coherent system based on the “contractual liability theory.” The pre-revision Japanese Civil Code’s provisions on the seller’s liability for warranty, much like those in the Korean Civil Code, were characterized by a highly complex regulatory framework and content. Reorganizing such provisions from a new theoretical perspective was undoubtedly a significant legislative challenge. This paper seeks to trace not only the results of the revision but also the process through which the simplification of regulatory content was realized. The revised Japanese Civil Code restructured the seller’s liability for warranty as a special rule of non-performance under the “contractual liability theory.” It explicitly provides that when a non-conformity to the contract is recognized, the buyer is entitled to remedies such as the right to demand cure, the right to reduce the purchase price, the right to claim damages and to terminate the contract based on general principles of non-performance. As a result of the revision, the scattered provisions of the pre-revision Civil Code governing the seller’s liability for warranty were unified into a single framework of liability for non-performance due to non-conformity with the contract. Coincidentally, in Korea, the Ministry of Justice's Civil Code Revision Committee, launched in 2023, has been working on a comprehensive revision of the contract law, and the draft amendment has recently been disclosed. The draft amendment, like Japan’s revised Civil Code, integrates various types of warranty liabilities by distinguishing between defects in rights and defects in goods, and it provides the buyer with remedies such as the right to demand cure, the right to reduce the purchase price, the right to claim damages, and the right to terminate the contract. It also introduces special provisions on the period for exercising rights in cases of defects in goods. However, there are differences from Japan’s revised Civil Code, including the Korean draft’s retention of the concept of defects, its use of the buyer’s awareness of a defect as a subjective condition to exclude the buyer’s rights, and its sequence of remedies (cure, termination, price reduction, and damages). Japan’s revised Civil Code serves as a valuable comparative legal resource for understanding and analyzing the Korean Civil Code Revision Committee’s draft. Future studies comparing the seller’s liability for warranty under the Korean draft Civil Code (or the revised Korean Civil Code) and the Japanese revised Civil Code are anticipated.