難解な (nankai na) or 不可解な (fukakai na) would mean "arcane" (unfathomable) in Japanese.
Possible improvement:
秘儀的な- (adj) (higitekina) is also a word used in Japanese as equivalent of 'arcane'.
Arcanus
The Japanese word for cute is Kawaii, The Japanese word for scared Kowai
Japanese word for surender
'Yorokobi' is a Japanese word for joy.
The Japanese word for sheep is hitsuji.
You may say 'shinpiteki,' written: 神秘的
Arcanus
arcane
Jack used his knowledge of the arcane arts to magically transform Bruno into a frog.
The anagram word is arcane. The word uses all six letters.
The word arcane means "known or understood by very few" or "mysterious".It is used as an adjective and usually comes directly before the noun it is describing.While in Africa, he observed some arcane religious rituals.She knew a lot about Sanskrit grammar and other arcane matters.
arcane
hidden, covert, arcane, obscure, esoteric, classified,
how to play arcane on fudgegames
Anton Arcane was created in 1972.
Arcane Path was created in 2004.
Arcane Device was born in 1949.