ISHIHARA intended to expand the society by incorporating prominent figures in the political and economic circles as well as the military, and besides NAKAGAWA, he also invited the lieutenant general (army) and baron Takeo KIKUCHI, major general (navy) Jiro NANGO, lieutenant general (navy) Tomojiro Chisaka, general (army) Kunishige TANAKA, general (navy) Michita HARA, and the diplomat Kumataro HONDA among others, to participate in the society.
石原は「神武会」に政財界や軍部の大物を参加させることで会を発展させようとし、中川のほか菊池武夫陸軍中将・男爵、南郷次郎海軍少将、千坂智次郎海軍中将、田中国重陸軍大将、原道太海軍大佐、外交官の本田熊多郎らにも参加を持ちかけていた。