Who is next in line, and who's left?
Naruhito, who ascends the throne on Wednesday, is the elder of Akihito's two sons. A musician and avid hiker, the 59-year-old Naruhito spent two years at Oxford and wrote a paper on the 18th century Thames River transport systems after studying history at Gakushuin University, a school formerly for aristocrats. His wife, Masako, a Harvard-educated former diplomat, is recovering from stress-induced conditions she developed after giving birth to their daughter Aiko amid pressure to produce a boy.
Aiko, 17, is barred from inheriting under Japan's male-only succession law, and the line goes to Naruhito's brother, Fumihito, better known by his childhood title, Akishino. Fumihito's 12-year-old son, Hisahito, would be next. Discussions on changing the law to allow female succession quickly ended with Hisahito's birth, but they are expected to resume, with Akihito's abdication raising concerns about the royal family's future. Most Japanese support female succession despite opposition by conservatives in the government and its ultra-right-wing supporters, who want the family to be a model for a paternalistic society.