Japan's Princess Kiko is due to give birth on Wednesday (September 6, 2006) and if she has a boy he would be the first Japanese imperial heir born in more than 40 years. The 39-year-old princess is the wife of Emperor Akihito's second son, Prince Akishino, who was born in 1965. She is scheduled to give birth by a Caesarean operation because of pregnancy complications, although the couple already have daughters Mako, aged 14 and Kako, 11. Japan's 1947 imperial succession law allows only males descended from an emperor to inherit the throne and neither of Emperor Akihito's two sons has a boy of his own. Prime Minister Junichiro Koizumi had planned to revise the law to give women equal rights to ascend the throne, which would have made Crown Prince Naruhito and Crown Princess Masako's four-year-old daughter, Princess Aiko, second in the line to the throne after her father. The plan was opposed by conservatives eager to maintain a males-only tradition they say stretches back more than 2,000 years -- and it was postponed when Princess Kiko became pregnant. The birth of a boy -- who would be third in line to the throne after Naruhito and Akishino -- looks likely to dampen debate on revising the law. Experts agree reform would still be needed eventually, however, since ensuring future male heirs is difficult without a royal concubine system -- which was ended by Emperor Akihito's father, Hirohito. Japanese media are set to give Wednesday's expected birth massive coverage, especially if it is a boy, but many people seem more concerned with the health of the mother and child than the baby's gender. "I don't think people are all that keen for a boy. Many ordinary Japanese citizens think it doesn't matter if it's a boy or a girl," said Masako Watanabe, aged 32, who was visiting Tokyo's Suitengu Shrine with her husband and daughter. Noriko Honma, a 33-year-old mother who's expecting another baby, said: "The current situation of the royal family might make one think that a boy would be ideal, but I don't think that Princess Kiko cares about it. All she is hoping for must be to have a healthy baby," said Honma. Another mother, Yuki Ishizaki, 35, said she's sympathetic to Crown Princess Masako, who has been under social pressure to produce a male heir. "Considering Princess Masako's position, I hope it will be a girl. The birth of a boy would put too much pressure on her to produce a male heir of her own," said. The birth is the latest chapter in a saga that has grabbed media attention since Crown Princess Masako suspended her public duties more than two years ago due to a mental illness caused by the stress of rigid royal life, including pressure to bear a male heir. As a diplomat before her marriage, Masako had hoped to use her professional skills when a princess, but the ambition was said to have been blocked by conservative palace officials.