Japan uses a peer-to-patent examination process to assess patents. This process invites the public to share information, knowledge, and expertise with patent examiners about the patent applications. Very often, valuable information such as prior art documents pertinent to reviewed applications are obtained.
One of the main criteria in the rating is the interest manifested by competing companies, which in this case was very high with 13 competing companies commenting on the patent application.
Source: R744.com