Passing Tsuneyasu Takeda on the street, one would think he was just another eager young businessman. His suit is immaculate and his face unremarkable. Yet this is the man who, if history had been kinder, could have assumed the Chrysanthemum Throne.
Instead, at the age of 30, he works for a foundation that supports elderly Japanese living abroad and is about to publish a scholarly work on Emperor Komei, who ruled in the 19th century.
His smile and manners are disarming - particularly when he lets slip that his hobbies are cooking and karaoke - but when it comes to his vision of the future of the imperial family, his opinions are unshakeable. As a member of one of the 11 families who were forced to drop their royal association by the US occupiers after the second world war and become commoners, he believes a woman should never become empress.
'It's not a matter of discrimination against females, but if Princess Aiko has a son or a daughter then that child will still be following the female line of succession,' said Mr Takeda, who has been thrust into the spotlight at an opportune time for a nation that is debating the fate of a family running out of heirs.
Princess Aiko - who is four years old - is the only child of Crown Prince Naruhito and Crown Princess Masako, and Japan has been consumed by the question of whether the law should be rewritten to allow a woman to assume the throne.
And while public opinion seems to be firmly behind revisions and giving the title to the first born of the family, resistance is growing from the right wing, traditionalists, politicians and the elders of the dominant Shinto religion.