Seiza chair cover I made a long time ago

This is a seiza chair cover I made when my children were little. I used cardboard and milk cartons to make a seiza chair, and then covered it with a seiza chair cover made from my child's old, holey pajamas. When studying at the living room table, sitting directly on the floor made the table too high, but putting them in a chair made the table too low. Furthermore, for children not used to seiza, this actually worked out perfectly! The idea was to sit in the seiza position, sandwich the chair between their legs, and then lower their hips to sit.