As Japan’s Princess Aiko turns 20, what her ‘boring’ coming-of-age reveals about an imperial family in crisis

• Observers agree a statement released on Aiko’s behalf to mark her 20th birthday was kept as vanilla as possible to deny the Japanese tabloids more fodder
• It comes as Japan grapples with a looming imperial succession crisis that some say could be solved by allowing women to sit on the Chrysanthemum Throne