On 6 March 1960 (昭和35年6月3日), the school received the first ever "Intangible Cultural Asset" designation given to a martial art by the Japanese government, naming Hayashi Yazaemon, Ōtake Risuke, and Iizasa Yasusada as its guardians. The Iizasa family dojo was also designated a Cultural Asset. The designation of Cultural Asset status shifted to the Chiba Prefectural Government in 1985 and the art was recertified, again naming Ōtake Risuke and Iizasa Yasusada as guardians. Ōtake Nobutoshi and Kyōsō Shigetoshi were also certified as guardians on 30 March 2004 (平成16年3月30日).