An old couple bought it as souvenir from a trip abroad, but they never used it to break walnuts since they can’t eat solid food, and instead used it as decoration. One day, it gained a will of its own and would crack any solid food, so the old couple requested Tsubasa’s father, who packed it in a barrel and sent it by delivery to his son with another item to deal with it.
However, Tsubasa ended up opening the barrel before his father could warn him about the doll and as the other item had not arrived yet, it would cause trouble in Tsubasa’s house, cracking even Tsubasa’s weapons and Rinne’s scythe. After a pretty hard period, the other item of Tsubasa’s father arrived, revealed to be a big walnut that actually contained instant glue to shut the doll’s mouth. As it still won’t rest, Tsubasa, unable to appease it, left it to Rinne with walnuts he had ordered.
- It's the second item Tsubasa would receive from his father through home delivery, which brings a case to be solved.