いたずら盛ざかり

noun

mischievous age; age when children are full of mischief

Refers to a stage in childhood when kids are especially playful and prone to pranks; often used with a nostalgic or affectionate tone.

• うちの子こは今いま、いたずら盛ざかりで、毎まい日にち何なにかやらかしてます。

  My child is at that mischievous age now and gets into something every day.

• いたずら盛ざかりの小しょう学がく生せいたちが公こう園えんで走はしり回まわっている。

  Elementary school kids at their most mischievous are running around the park.