JOURNAL OF ETHNIC AND MIGRATION STUDIES 971 surname to fill in the baby’s information. The staff gave the baby a Japanese first name, Yukito. A few months later, the immigration bureau learned that the mother’s name left in the letter was fake. After turning three, Yukito would have been able to acquire Japanese nationality as ‘a child born in Japan with unknown parents’.1 However, several days after Yukito’s first birthday, the mother called the hospital, saying she wanted to pick up her child. The orphanage staff instructed the mother about the formal procedure and the required documents. However, contact from the mother suddenly ceased. The orphanage staff hesitated ‘to make him Japanese’. The staff decided to start this procedure if the mother did not make contact again by Yukito’s ‘school entrance’ (six years old in Japan). There was no such contact, but the father did call, saying he had his own family and was not in contact with Yukito’s mother. However, he wanted to see his son’s photograph. Yukito and his father exchanged letters and photographs, but the father also stopped responding. However, because of this correspondence, by six years old, Yukito was confident that he was a Thai. The orphanage staff again hesitated to ‘make him Japanese’. In this way, Yukito grew up in a Japanese orphanage as a native-born stateless child. This vignette exemplifies some important trends of the abandonment of children by the migrant parent(s) who appeared in my interviews in Japan; abandonments were lengthy. Previous studies on citizenship and migration have tended to overlook abandoned children, partly because accepting countries typically have regulations to certify the nationality rights of abandoned children. For example, Mahdavi (2016) mentioned that ‘(a)ccording to Kuwaiti law, an abandoned child found in a mall or on a street corner whose parents are unknown will be eligible for citizenship’ (Mahdavi 2016, 124). In Japan too, the nationality law stipulates Japanese nationality ‘(w)hen both parents are unknown or have no nationality if the child is born in Japan’.2 However, children are seldomly abandoned without any vestige of parents. Rather, migrant parent(s) abandon their ‘impossible children3’ (Allerton 2018, 1082) gradually, showing hesitation, regret, and attachment. This article examines how this happens and the consequences of time and gradual abandonment on children’s statelessness. This article conceptualises the gap between the legal definition of abandoned children and the reality of ambiguous abandonment in the context of the passing of time as a crucial factor in the legal production of statelessness. The analysis focusses on the function of time for people whose lives are shaped by migration and law (Mahdavi 2016, 122); they fall in a nationality limbo in childhood, resulting in statelessness in adulthood – what I call the legal production of statelessness. In doing so, I integrate scholarly debates on statelessness with two theoretical frameworks on citizenship for ‘foreign-born natives’ (Mahdavi 2016, 125), or citizen aliens (Boehm 2012, 136) – people born and raised as country natives but classified as foreigners. I especially rely on Mahdavi’s argument on the ‘legal production of illegality’ (Mahdavi 2016, 122) and Gonzales’s argument on ‘the law and the clock’ (Gonzales 2016, 17). Policies rarely acknowledge migrants as multidimensional beings with intimate lives (Mahdavi 2016, 14). In her work on migrant mothers who abandon their children, Mahdavi argued that bad policies affect the creation of problematic situations of illegality or statelessness for migrant mothers and their children (Mahdavi 2016, 14–15). This article contributes to citizenship and migration studies showing that not only ‘bad’ but also ‘neutral-looking’ (Belton 2017, 5) policies and the affections of related people