高こう校こう時じ代だい

noun

one's high school days; high school years

Refers to the period of time when someone was a high school student. Often used in nostalgic or biographical contexts.

• 高こう校こう時じ代だいの友とも達だちと久ひさしぶりに会あった。

  I met a friend from my high school days for the first time in a while.

• 彼かれは高こう校こう時じ代だい、野や球きゅう部ぶに所しょ属ぞくしていた。

  He belonged to the baseball club during his high school years.