family register with D listed on the top of it with the presumption that165 he had acquired Japanese nationality by birth as a legitimate child of D and B.166 (A’s family name is the family name of D.) A had thus been, in reality, raised by C and B as the couple’s child while carrying D’s family name since birth. On a separate note B, the mother, acquired Japanese nationality by naturalization after A’s birth. A graduated from elementary/junior high/high school and university near Tokyo as a “Japanese national”. During his university studies, A obtained various national licenses, and he even visited several foreign countries with a passport under D’s family name. A also studied abroad, including in ROK as a Japanese student. In the late 2000s, after A had turned 30, a lawsuit to confirm the non-existence of a parent-child relationship was filed against D in order to reflect the actual father-child relationship between A and C while also reflecting C and B’s wish. When A was in his early 30s, the court decision to deny his current paternal descent from D was finalized. However, against the expectations of A and others involved, A was considered to have never possessed Japanese nationality going back retroactively to the time of birth, as the prerequisite for acquiring Japanese nationality based on Article 2(i) of the preamendment Japanese Nationality Act was lost due to the severed father-child relationship with D. A was deleted from D’s family register. C recognized his paternity over A as soon as the court decision to deny D’s paternity over A was finalized. However, A’s Japanese nationality was not recovered even with another Japanese male’s recognition of paternity over him, in accordance with Supreme Court case law ruling that recognition of paternity does not have a retroactive effect in relation to the acquisition of nationality.167 165 Article 2 (i) (paternal jus sanguinis) of the Nationality Act, before the 1984 amendment (which came into force in 1985). 166 On the family register (koseki), see the description in Category M: Persons without a Japanese family registry, 1. (1). On children born in wedlock, see note 180; on the creation of the family register, see note 168; and on the procedure for confirmation of the non-existence of a parent-child relationship, see note 181 below. 167 “Article 2 (i) of the [Nationality] Act adopts both a paternal and maternal jus sanguinis principle in relation to the acquisition of Japanese nationality at birth; it does not mean that the blood line, which merely shows the biological origin of a human being, is held in absolute view; the provision aims to grant nationality when there is a legal parent-child relationship between the child and a Japanese father or mother at the time of birth, for it means that the child has a close link with Japan. And, whereas it is desirable to make a definite decision on the acquisition of nationality as much as possible at the time of birth, and whether or not the child would later be recognized by the father is unconfirmed at the time of birth, there would be reasonable grounds for Article 2 (i) not to retroactively recognize a legal father-child relationship at the time of birth based on a later recognition by a Japanese father, and not to recognize acquisition of Japanese nationality at birth through a later recognition by the father alone” [italics added by the author]. The Supreme Court (Petty Bench II), Judgment, 22 November 2002 (Heisei 14 Nen), Shuumin Vol. 208, p. 495. 79