noun
nursery school sleepover
An overnight stay event at a nursery school or kindergarten, where children sleep at the facility as part of a group activity.
来週、幼稚園でお泊まり保育があります。
Next week, there will be a nursery school sleepover at the kindergarten.
お泊まり保育で、子どもたちはみんなで一緒に寝ました。
At the nursery school sleepover, the children all slept together.
Compound of お泊まり (o-tomari, 'staying overnight', from 泊まる tomaru) + 保育 (hoiku, 'nursery care').