On October 1, 2023, Japan deposited its instrument of accession to the United Nations Convention on International Settlement Agreements Resulting from Mediation (the “Singapore Convention on Mediation”) with the UN Secretary-General, becoming the 12th state party to the treaty. The Convention entered into force in Japan on April 1, 2024. As of the date of this article (December 9, 2024), 57 countries have signed the Convention, and 14 have ratified it.

The Singapore Convention on Mediation aims to grant enforceability to settlement agreements reached through international mediation. Before the Convention, even if parties successfully reached a mediated settlement, enforcement depended on voluntary compliance, leaving no mechanism for compulsory enforcement. Recognizing this gap, the Convention establishes a framework enabling the enforcement of such agreements in signatory states, provided specific conditions are met. Japan’s accession to the Convention is notable for the following two features:

(1) Accession Rather Than Ratification

Multilateral treaties are typically finalized through the adoption of the treaty text, followed by signing and ratification by participating states. “Accession,” in contrast, allows states that did not participate in negotiations or sign the treaty to later express their consent to be bound by it. Japan opted for accession—a one-step process—instead of the two-step process of signing and ratification. This approach likely reflects Japan’s deliberate consideration of whether to adopt the Convention, whether to extend enforceability to domestic mediation agreements, and whether to make the “opt-in” reservation discussed below.

(2) Opt-In Reservation

A more significant feature of Japan’s approach is its opt-in reservation. Under this reservation, the Convention applies only if the parties to a settlement agreement explicitly agree to its application (Article 8(1)(b) of the Singapore Convention).

For example, consider a case where Japanese company J and Sri Lankan company S engage in mediation, resulting in a settlement agreement requiring S to pay $500,000 to J. Both Japan and Sri Lanka are parties to the Convention. However, Japan has made the opt-in reservation, whereas Sri Lanka has not. If J seeks to enforce the settlement in Sri Lanka, it can do so under the Convention without further action. Conversely, if S wants to enforce the agreement in Japan, it must ensure that the settlement includes an explicit opt-in provision.

This opt-in reservation adds complexity to the legal analysis and requires careful consideration of factors such as the nationality of the counterparty and the location of assets subject to enforcement. Attorneys must conduct thorough analyses and provide tailored advice to clients in such cases.

In Japan, in parallel with the Diet deliberations on the approval of treaties, it is common for the Diet to deliberate on the development of domestic laws to accept the treaties into the domestic order. With regard to the Singapore Convention on Mediation, a new law, the “Act on the Implementation of the United Nations Convention on International Settlement Agreements through Mediation,” was enacted in conjunction with the conclusion of the Convention to implement the Convention domestically. The new law has been in effect since April 1, 2024, the same date as the domestic entry into force of the Singapore Convention on Mediation in Japan. A more detailed explanation of this law can be found in previous columns, but its implementation ensures the smooth enforcement of international settlement agreements in Japan if the prescribed requirements are met.

The year 2024 has been pivotal for Japan’s adoption and implementation of the Singapore Convention on Mediation, marking a significant step toward revitalizing international mediation. In my engagements at international conferences and seminars, I have observed growing interest among businesses and legal practitioners in this field.

While some critique the Convention for limited usage, it is essential to recognize that international mediation often results in voluntary compliance. The limited reliance on the Convention can be seen as a testament to the effectiveness of mediated settlements and the mutual satisfaction of the parties involved. Beyond enforceability, the Convention provides assurance to parties engaging in international mediation, promoting trust in the process.

Despite the growing interest, Japanese businesses have yet to fully realize the potential of international mediation. For instance, only 3.4% of cases handled by the Singapore International Mediation Centre (2014–2023) involved Japanese parties. This figure, while among the top 10, pales in comparison to countries like China (16.5%), the U.S. (7.3%), and South Korea (4.3%). Increased efforts to raise awareness of the benefits of mediation among Japanese businesses and practitioners are warranted.

Finally, I would like to introduce the JIMC-SIMC Joint Protocol as a highly practical tool for Japanese businesses. This collaboration between the Japan International Mediation Centre (JIMC) and the Singapore International Mediation Centre (SIMC) allows for the appointment of two mediators—one from each center.

For example, in a case involving Japanese company J and Sri Lankan company S, a Japanese mediator and a Sri Lankan mediator could be appointed. This approach ensures cultural and linguistic familiarity for Japanese parties while enhancing trust in the mediation process. Furthermore, administrative fees are reasonably set, making this protocol accessible to small and medium-sized enterprises or cases involving modest dispute amounts.