The planned engagement of Princess Mako and Kei Komuro, a 25-year-old commoner, has highlighted a critical question facing the Imperial family that is likely to spark public debate: Can the Imperial system survive without drastic reforms to its succession system?

Most experts say no, and that major reforms will eventually be needed if Japan wants to retain the Imperial system.

Article 1 of the Imperial House Law reads: "The Imperial Throne shall be succeeded to by a male offspring in the male line belonging to the Imperial Lineage."