sleeping face
Refers to a person's face while they are asleep, often with a nuance of peaceful or unguarded expression.
赤ちゃんの寝顔はとてもかわいい。
The baby's sleeping face is very cute.
疲れていたのか、彼の寝顔はとても穏やかだった。
Perhaps because he was tired, his sleeping face looked very peaceful.
Looking at my child's sleeping face makes all my tiredness disappear.
I secretly took a photo of his sleeping face.
My dog has a very cute sleeping face.
The baby was sleeping with a peaceful expression on its face.