This paper focuses on children in Japan who begin using mobile phones (keitai) while in elementary school and will discuss aspects of parental–child relationships that involve keitai use. Firstly, this paper presents an overview of a Japanese society presently immersed in mobile media, focusing particularly on the spread of mobile media use to younger Japanese children. Data are presented from two research projects and analyzed to examine the cause of, and circumstances that lead to, child keitai use. Increasing social anxieties about safety and parental concern have reportedly led to increasing perception that keitai use is valuable in times of emergency, or in order to prevent crime, leading to a shift in attitudes towards children's keitai use: that which was formerly considered “unnecessary” has now become “necessary”. However, the anxiety about safety is shared by almost all people and is therefore not itself a deciding factor regarding children's keitai ownership. Keitai usage is, instead, prompted by several factors, some of which are not shared by children and parents. From this rift in reasoning emerges a game of tug-of-war over ownership and use between children and parents.
