オリジナルシナリオ

noun

original scenario; original screenplay

Refers to a story or script created from scratch, not based on existing material. Common in film, TV, and game contexts.

• この映えい画がはオリジナルシナリオで制せい作さくされた。

  This movie was produced from an original screenplay.

• 彼かれはオリジナルシナリオを書かくのが得とく意いだ。

  He is good at writing original scenarios.