When someone is trying to patent something in Japan that is not unique or for some other reason should not be patentable, third parties are allowed to intervene in the patent application process to argue against granting the patent. These interventions can even be filed anonymously and, if successful, will prevent the granting of a patent for products that are not unique or not patentable for some other reason.
It is also possible to use the court system to invalidate an improper patent after it has been granted, but this method is more expensive and time consuming and potential profits might be lost before a final result is reached. When possible, it is far better to ensure that the patent is not granted in the first place, rather than have it invalidated after the fact.
If you have any questions about licensing intellectual property please contact our office for a legal consultation.