秘中の秘

ひちゅうのひ

top secret

黙秘

もくひ

keep silent, keep a secret

秘奥

ひおう

secrets, mysteries

秘本

ひほん

treasured book, secret book, pornographic book

秘術

ひじゅつ

secret art, the mysteries

秘部

ひぶ

secret place

秘苑

ひえん

secret garden, private garden

秘匿

ひとく

hiding, concealment

秘仏

ひぶつ

Buddhist image normally withheld from public view

秘薬

ひやく

nostrum, secret medicine

秘説

ひせつ

secret theory

守秘

keeping a secret; secrecy; confidentiality

秘法

ひほう

secret formula, secret process

秘蔵

ひぞう

treasure, prize, cherish, treasured

秘策

ひさく

secret plan or measures

秘録

ひろく

secret notes, confidential papers

秘儀

ひぎ

secret ceremony, ritual, sanctum sanctorum

秘湯

ひとう ひ とう

little-known hot spring, secret hot spring, secluded hot spring

秘鑰

ひやく

secret key