本ほん筋すじ

noun

main thread; main plot; main point

Refers to the central storyline of a narrative, or the essential point of a discussion. Often contrasted with digressions or side issues.

• 話はなしが本ほん筋すじからそれてしまった。

  The conversation strayed from the main point.

• この小しょう説せつの本ほん筋すじは、家か族ぞくの絆きずなを描えがいている。

  The main plot of this novel depicts family bonds.