後こう夜や祭さい

noun

closing party; closing event of a festival

Typically refers to the final celebration or ceremony at a school festival (学園祭) or similar event, often with performances or a wrap-up gathering.

See also: 学園祭

• 学がく園えん祭さいの後こう夜や祭さいで、花はな火びが打うち上あげられた。

  Fireworks were set off at the school festival's closing event.

• 後こう夜や祭さいの準じゅん備びは、実じっ行こう委い員いんが中ちゅう心しんになって進すすめている。

  The executive committee is taking the lead in preparing for the closing party.