Some images of Nyorai (Tathagata), Bosatsu (Bodhisattva), Myoo (Vidyaraja), and Tenbu (Celestial beings) are treated as hibutsu, and statues that typically do not fall in the category of 'Buddhist image,' including those of Suijaku (literally, trace manifestation) as Zao Gongen (the highest-ranking deity worshipped in Japanese mountain asceticism), and the Soshizo (sect founder images), as the image of Jianzhen are also treated as hibutsu.
如来像、菩薩像、明王像、天部像のいずれにも秘仏となっているものがあり、厳密には「仏像」の範疇に入らないが、蔵王権現のような垂迹像、鑑真像のような祖師像にも秘仏となっているものがある。