Kenkokukai/National Foundation Society (a.k.a. State Foundation Society, a.k.a. The Society to Build the Country) was an ultranationalist organization for "the creation of a genuine people's state based on unanimity between the people and the emperor".
Source.
Another useful excerpt...
japanese badge
kenkokukai badge
national foundation day badge
national foundation society badge
national foundation society membership badge
建国会徽章
建国祭記念章
建國會會員章
建國祭之章
