In brief
A bill to amend the Seed and Seedlings Act (SSA) — Japan’s plant variety protection statute — was submitted to the National Diet on 3 April 2026. The proposed amendments have been released by the Ministry of Agriculture, Forestry and Fisheries (MAFF). The changes would strengthen and improve the enforceability of breeders’ rights in response to a diversification of infringement methods and continuing concerns over the unauthorized overseas outflow of valuable plant varieties from Japan to other countries.
Overview of the proposed amendments
1. Extension of terms of breeders’ rights
The bill proposes extending the duration of breeders’ rights by 10 years:
- From 25 years to 35 years for non perennial plants
- From 30 years to 40 years for perennial plants
According to MAFF, modern plant breeding increasingly requires the incorporation of multiple traits (e.g., heat tolerance, disease resistance and higher yields), necessitating advanced technology, substantial investment and long development cycles. In addition, the process of establishing production areas for improved varieties takes many years due to the need to disseminate cultivation techniques, prepare seedlings and wait for them to mature. The proposed extension is intended to better align legal protections with these commercial realities and remains consistent with international standards under the UPOV Convention.
2. Strengthened measures to prevent leakage of new varieties
a. Expansion of provisional protection during the application period
While the SSA already provides provisional protection for plant varieties from time that an application is published until its registration, the amendments would expressly enable breeders to seek injunctive relief against exports of seedlings and other propagating material for applied for varieties during this interim period.
b. Regulation of storage for export purposes
To enhance the effectiveness of restrictions on unauthorized overseas exports of propagating materials, the amendments clarify that storage for the purpose of export (e.g., warehousing seedlings destined for shipment abroad) may infringe breeders’ rights.
This would operate as an exception to the exhaustion of rights doctrine and extend protection to preparatory acts occurring prior to actual export, building on a 2020 SSA amendment that first used this rationale to stem the unauthorized overseas outflow of Japanese plant varieties.
c. Enhanced civil remedies for infringement
The bill proposes several measures to strengthen the legal remedies available to breeders.
- Damage calculation: The amendments clarify that damages caused by infringement may exceed ordinary license fees, reflecting the fact that licensors typically grant lower fees to parties who seek a license before exploitation than to those who only do so after infringement is discovered. This change would address the concern that infringers currently have less incentive to obtain licenses in advance because their liability is effectively capped at the level of ordinary royalties.
- Presumption based on variety name: Where seedlings are sold under a registered variety name, courts may presume that they are of that variety without requiring physical inspection, partially shifting the burden of proof from right holders to alleged infringers.
These measures are intended to improve the practical enforceability of breeders’ rights, particularly in cases where evidentiary hurdles have made infringement litigation difficult.
d. Restriction on re importation of registered varieties
The amendments clarify that where a breeder or other right holder transfers propagating material for a registered variety abroad, the rights to the use of the material apply in Japan — including re importation of the material. This provision is designed to prevent circumvention of domestic protections via transactions with overseas entities.
e. Protection for leasing of seedlings
The amendments would expand breeders’ rights by expressly including leasing (rental) of propagating material. This is particularly relevant where breeders retain ownership of seedlings while making them available to others under leasing arrangements, ensuring that these business models are clearly protected under the SSA.
3. Additional procedural and enforcement measures
Other notable proposals include the following:
- Priority examination of variety registration applications where early commercialization is particularly important
- Introduction of a system, modelled on the Patent Act, allowing courts to solicit opinions from the public through an amicus brief–type mechanism to assist in the resolution of disputes
- Doubling of administrative fines for violations of the obligation to use registered variety names from JPY 100,000 to JPY 200,000
4. Effective date
The majority of the amendments are scheduled to enter into force on 1 December 2026, with the provisions extending the terms of protection and restricting re importation taking effect upon official publication of the law.
Position of the proposed amendments within the UPOV framework
If enacted as proposed, the amendments would further reinforce the distinctiveness of the Japanese plant variety protection regime, which already contains a number of features that are not commonly found in other jurisdictions and that go beyond the minimum standards set by the UPOV Convention. Japanese plant variety protection law has increasingly emphasized preventive and border focused measures, particularly in response to risks associated with cross border movement of plant materials.
Importantly, Japan has observed that many Japanese plant varieties are not protected in foreign jurisdictions, often because plant variety registrations are not sought or obtained in these countries. In such cases, once propagating material is exported, effective legal remedies may be limited or unavailable under foreign law. The proposed amendments therefore place particular emphasis on preventing unauthorized exports of plant materials from Japan rather than relying on post export enforcement abroad.
Taken together, these developments suggest that Japan is continuing to position the SSA as a front line IP protection tool to manage cross border risks while remaining consistent with the UPOV Convention framework. The UPOV Convention seems to allow a degree of national discretion in shaping the scope and enforcement of plant variety protections, at least with respect to the issues addressed by the proposed amendments. This discretion may be used to enhance protection — particularly in relation to export related risks — while remaining within the UPOV framework.
Practical implications
Breeders, exporters, licensees and logistics service providers — especially those operating internationally — may want to reassess their export controls, storage practices, licensing structures and compliance programs in light of the proposed amendments. Breeders may also want to consider filing for protection of their plant varieties in Japan in order to benefit from the distinctive features of its plant variety protection regime. Whether, and to what extent, other jurisdictions adopt similar approaches to strengthening plant variety protection should be monitored going forward.