"藁人形 (wara-ningyou, straw dolls)" are Japanese-style Voodoo dolls.
They are usually made of a few bundles of straw, and are used in a traditional Japanese curse ritual known as "丑の刻参り (Ushi no Koku Mairi)." This ritual is frequently translated into English as "Midnight Anathema Ritual." Every night, the ritual takes place during "Ushi no Koku," the name of a time period used in traditional Japan, representing 1:00 to 3:00 in the morning. The person who executes the curse wears white clothing , paints face powder on his/her face, puts a trivet on his/her head , stands candles on that trivet, wears single-toothed geta, and at a sacred tree growing in a shinto shrine, selects a wara-ningyou for a person he/she detests, and nails a gosun-kugi (a large nail about 5 inches in length) to the doll. The first person to do this kind of curse in Japan was a very jealous woman who was called "the Bridge Princess of Uji." But the procedure she used in her ritual is a little different from the "Ushi no Koku Mairi" ritual that has been passed down to today. You may have heard the words "wara-ningyou" and "gosun-kugi" in the intro to "魔理沙は大変なものを盗んでいきました(Marisa stole the precious thing)."