いいこ

good boy/girl

→ 良い
phrase Rare #36,047
good boy/girl An affectionate expression used for a well-behaved child, often also meaning “be good” when telling a child how to behave. Usually written いい子.
JA: お母さんが帰るまで、いいこで待っていてね。
EN: Be a good boy/girl and wait until Mommy gets back.

いますぐいくからいいこいなさい

I'm coming right now, so be a good girl, okay?

— 千と千尋の神隠し (2001)

あけていいこだから・・・

Open up, be a good kid…

— 千と千尋の神隠し (2001)

いいこだから

Because you're a good kid.

— 天空の城ラピュタ (1986)

いいこおねんねしてて

Be a good little one and go to sleep, okay?

— 千と千尋の神隠し (2001)

いいこおねんねしてたのに

You were sleeping so peacefully, too.

— 千と千尋の神隠し (2001)