Yamabudoudanshi
Shohin
The official Kokufu website is the Nippon Bonsai Kyokai site. They do have a list of board members, and other rolles for the organization on the site, but unfortunately no lists of entries. I even searched previous years for entry lists and the like and came up with nothing.Usually, the name of the artist is on one of the the boards in front of the bonsai. Of course, that is not as helpful as an online overview file. I know that this is not uncommon to have. For satsuki bonsai, there are usually lists available of all competition/show entries and authors/artists. If the Kokufu Ten has an official website (in Japanese of course), you might have some luck looking around there. But as Yamabudoudanshi says, he checked and it is not available(?)..
Here's the site, https://bonsai-kyokai.or.jp/