悠仁親王 (Prince Hisahito), the youngest prince in the Japanese
royal family, turned three today. He is third in line to become
the Emperor of Japan. Next in line behind the current emperor is
the Emperor’s oldest son (Prince Hisahito’s uncle) Prince
Naruhito, and second in line is the Emperor’s youngest son
(Prince Hisahito’s father) Prince Akishino. If the current
Emperor’s oldest son (Prince Naruhito) had a son, he would be in
line to the throne before 悠仁親王 (Prince Hisahito)…but he has a
daughter (Princess Aiko) and no other children. And 悠仁親王 (Prince
Hisahito) has two older sisters, but no brothers. So before 悠仁親王
(Prince Hisahito) was born, the Japanese government was in a
quandary about who would succeed the throne. They considered
changing the law to allow Japan to be headed by a female
empress, so that Princess Aiko could eventually take the
throne…but her cousin 悠仁親王 (Prince Hisahito) was born, so that
issue became moot.