原作

original work

ɡ ẽ̞ ɰ̃ s a̠ k ɯ̟
original; source + work, creation
noun Rare #40,367
original work Often refers to the original source material, such as a novel or manga that was adapted into a film, anime, or other work.
JA: この映画の原作は人気の小説です。
EN: The original work of this movie is a popular novel.

そのドラマ原作違っている

That drama is different from the original work.

その翻訳原作見事に忠実であった

That translation was remarkably faithful to the original.

その映画は原作ほどおもしろくなかった

The movie wasn't as interesting as the original book.

原作学校の教科書として書かれた

The original work was written as a school textbook.

Sounds similar to