直ちょっ系けい

noun, noun which may take the genitive case particle 'no'

direct line of descent; direct lineage

Refers to a direct bloodline or succession without branching, such as parent-to-child. Often used in legal, historical, or family contexts.

• 彼かれは徳とく川がわ家けの直ちょっ系けいの子し孫そんだ。

  He is a direct descendant of the Tokugawa family.

• 直ちょっ系けいの親しん族ぞくのみが相そう続ぞく人にんとなる。

  Only direct-line relatives become heirs.