Translation guide
The genre of science fiction, often abbreviated as SF in Japanese. The English abbreviation 'sci-fi' is widely understood but less common in native Japanese usage.
Referring to the genre of science fiction in general, including literature, film, and other media.
The standard Japanese abbreviation for science fiction, pronounced エスエフ. This is the most common and natural way to refer to the genre.
私はSF映画が好きです。
I like sci-fi movies.
彼はSF小説をたくさん読んでいる。
He reads a lot of sci-fi novels.
The full loanword from English. Used in formal or explanatory contexts, but less common in everyday speech.
この作品はサイエンスフィクションの古典です。
This work is a classic of science fiction.
Literally 'imaginative science', a more literary or descriptive term. Rarely used in modern conversation; may appear in older texts or specific contexts.
空想科学小説は未来の技術を描く。
Science fiction novels depict future technology.
Describing something as being related to or characteristic of science fiction, e.g., 'a sci-fi story', 'sci-fi elements'.
Use the noun SF followed by the possessive/no-adjective particle の to modify another noun. This is the standard way to say 'sci-fi (something)'.
SFの世界観が面白い。
The sci-fi world-building is interesting.
あの映画はSFの要素が強い。
That movie has strong sci-fi elements.
Adding 的な (teki na) makes it more explicitly adjectival, meaning 'sci-fi-like' or 'science-fictional'. Slightly more emphatic than SFの.
そのデザインはとてもSF的だ。
That design is very sci-fi.
While the English word 'sci-fi' is recognized by many Japanese speakers, especially those familiar with English media, it is not the standard term. Using SF (エスエフ) is much more natural and common. Saying 'サイファイ' (saifai) might be understood but sounds like a direct loan from English and is not typical.