A water absorption treatment material includes a first grain and a second grain that absorb a liquid. The first grain includes a first core portion and a first coating portion. The first core portion has a grain-like shape. The first coating portion contains an adhesive material, and covers the first core portion. The second grain includes a second core portion and a second coating portion. The second core portion has a grain-like shape. The second coating portion contains an adhesive material, and covers the second core portion. The thickness of the second coating portion is smaller than the thickness of the first coating portion.