This presentation considers the relationship between materiality and affect, based on research conducted at a "stuffed animal hospital" in Japan. They repair stuffed animals requested by their owners. They treat stuffed animals the same as humans and treat them as if they are living things. Generally, such phenomena tend to be approached from a perspective of animism, but this presentation will avoid this. Because majority of people in Japan do not recognize stuffed animals as living things. Additionally, when repairing stuffed animals, most companies treat stuffed animals as mere objects. An approach from a perspective of animism risks essentializing the "stuffed animal hospital" in Japan. The focus of this presentation is on the impact that changes in the materiality of stuffed animals have on the relationship between the owner and the stuffed animal. For example, I heard narratives about how relationships change as a result of changes in materiality, such as when a stuffed animal's ribbon was removed and it became talkative, or when its mouth was removed, it became more expressive. Yoshida [2016], who examined masques, points out that the materiality and physical changes of masks can change the function of masks and bring out new performances from performers. In the case of stuffed animals as well, their physical changes might influence the relationship with their owners. On the other hand, some informants say that even though the materiality of stuffed animals change due to passing long years or due to treatment, their "aura" remains. Some informants say that even if the materiality of the stuffed animal change significantly due to the necessary treatment, they are confident that they can still love it as "the same my child." However, some informants say that if the materiality of the stuffed animal change significantly, his/her name will also change.