– The Seeds and Seedlings Law No. 83 of May 29, 1998, and amendments, to converge with UPOV (1991 Act); revision for duration of protection, effective from December 1, 2005.
– The Revision effective from April 1, 2021.
– The Revision effective from April 1, 2022.

– International Convention for the Protection of New Varieties of Plants (UPOV), since September 3, 1982, 1991 Act, effective from December 24, 1998.

Applicant: the breeder or his successor. An applicant must, if an individual, be a citizen of, or be domiciled in Japan or another UPOV country or, if a legal entity, have a registered office therein.

Agents: there is no specific law or regulation with regard to agents, but in practice, a domestic agent is requested if the applicant is a foreigner.

Kinds of plants: the breeder’s right can be protected on varieties belonging to the species designated in the regulation.

Conditions for protection: plant varieties must be new, distinguishable, homogeneous and stable.

Novelty: only the first deposit can be registered if two or more applications are filed with respect to the same single variety.

Distinctiveness: the variety to be protected must have characteristics by which the plant can be distinguished from any other known plant.

Homogeneity: the variety to be protected must be homogeneous in characteristics as a whole.

Stability: the characteristics of the variety must be sufficiently fixed that a plant having the same characteristics may be repeatedly bred by normal propagation techniques.

Filing requirements for an application (to be sent to resident agent):
1. Application form and specification;
2. Photograph, seeds or culture of fungi when they are the object for protection, seeds of parent plants when a crossbred variety is the object, or documents describing a place or method of maintaining a plant when seeds or seedlings are not propagation materials;
3. Certified priority documents, if a Convention priority is claimed (within three months from the filing date);
4. Assignment document if an application is filed by the assignee;
5. Documents to prove nationality or residence if the applicant is a foreigner who is not domiciled in or does not have a registered office in Japan;
6. Application fee.

An application is first examined with respect to the formality requirements. Then, the application is examined as to merit in accordance with the documents filed. If the Examiner determines that further investigation is needed, he can request the applicant to submit additional documents or samples, investigate the place where the plant is bred, or have a specialist breed the plant. If the Examiner determines that the application satisfies all the requirements, he shall make a decision for publication of the application.

Opposition: any third person can, within sixty days after the publication, submit to the Examiner relevant information to prove that the application should not be granted. If the Examiner determines that the application does not satisfy the requirements, it shall be rejected.

Appeal: the applicant can appeal against such a decision by filing a statement with the Minister of Agriculture, Forestry and Fisheries.

Duration: the protection lasts twenty-five years from the registration date, or in the case of ornamental, timber or fruit trees, etc., thirty years from the registration.

Effect of registration: any person other than a person to whom registration of a variety of plant is granted is prohibited from carrying out the following acts in relation to that plant: (1) to sell or to offer for sale seeds or seedlings, or to produce or import seeds or seedlings for the purpose of sale; (2) to breed a plant from a part of a plant other than a seed or seedling and to sell it, if the variety of plant belongs to those designated under the regulation; (3) to cross a registered fixed variety with another fixed variety so as to produce a crossbred variety and to deal with the resulting crossbred seeds or seedlings as in (1) above.

April 1, 2021 amendment: it allows the developer of a variety to designate the countries to which seeds and seedlings may be exported and the regions in which they may be grown. Violations of this, such as intentionally taking seeds or seedlings out of the designated countries, are subject to criminal penalties and compensation for damages. It is mandatory for those who transfer seeds of registered varieties in the course of business to indicate on the seeds and packaging that they are of registered varieties.

April 1, 2022 amendment: in order to enable the holder of the breeder's right to monitor the actual propagation of the registered variety, and to enable the holder of the breeder's right to respond appropriately to outflows, the permission of the holder of the breeder's right is required for home propagation of registered varieties by farmers.