秘蔵宝钥 (秘蔵宝鑰) mì zāng bǎo yào

mì zāng bǎo yào proper noun Hizō Hōyaku; The Precious Key to the Secret Treasury
Domain: Buddhism 佛教 , Subdomain: Japan , Concept: Canonical Text 典籍
Notes: See 祕藏寶鑰