Indoor shoes or slippers worn inside buildings, such as the indoor footwear used in school classrooms (also written 上履 or 上ばき).
小学校では上履きに名前を書いておく。
In elementary school, write your name on your indoor shoes.
玄関で外履きを脱いで上履きに履き替える。
Take off outdoor shoes at the entrance and change into indoor shoes.
上ばきを洗濯して乾かした。
I washed and dried my indoor shoes.