General Mountbatton had been sent as an ambassador of England to Japan, at the time he was a mere major general, a commission purchased for him by his well to do family. However, he was a young man, simple, licentious and prone to following his lusts rather than his discretion. He had engaged with a young Japanese woman, not a relationship, merely a dalliance with a beautiful orchid of the east. He had not expected much to come of their interaction, he thought they would amuse each other for a time an then he would return to England with no one being the wiser. That was not, however, what occured.

His father, an admiral of the fleet, came to Japan to visit his son and it was at this time that the girl made a rather alarming pronouncement. She was with child and her contention is that it was his. The plan had been to abandon the woman to the fate of all mothers of bastard children - but for one factor. The General's sister, was a witch - she had attended a magical school from the age of 11 when her condition had been revealed to her family. Her aunt Lissa was worried about the dangers of allowing a poor 'muggle' woman to birth a magical child and not make provisions insisted that they keep an eye on her until the time the child was born. Afraid that the superstitious 'foreigner' might take accidental magic as demonic. If she proved to be the generals, (as there was every chance that she 'entertained' more than one man) then provisions would be made.

At her birth Natsuko's close resemblance to her father comforted the General that she was in fact his child. Her mother had hoped that he would be harangued into a marriage but it was not to be. General Mountbatton claimed his daughter as legitimate, sending to Lyssa, who at this time shared her time between England and France. The General himself left Japan when his commission was complete. Natsuko never knew her mother but instead grew up in the magical society of her aunt, with whom she was unceremoniously deposited after her father died of brain fever in the tropics on another assignment. It was a world of well to do, high classed and aware at all times that her race made her very different to many children she was exposed to.

Little did Natsuko, or indeed the general know that her mother was soon after married to another man and bore another child, a girl who would be Natsuko’s half sister. This girl was also magical, as it transpired that their mother was magical but had never attended school and so had no ability to use or control magic. When Natsuko turned 11 she received her letter inviting her to study at Hogwarts but also an invitation to study at the magical academy in her native Japan. It was decided, for many reasons, not least of which her heritage, to send her to study in Japan, so that she would return when old and properly turned out enough to be considered proper in the eyes of society. So, she began her magical education abroad, with her aunt spending her summers in Japan so Natsuko did not return to England during the period. Everyone was told that her parents had been married, and that she was legitimate, well she was now anyway, she had been claimed by her father.

She completed schooling with fully golden robes. Now that her education is completed she has returned to England an heiress in order to be finished in the proper western fashion so that she might be prepared for marriage. Her aunt lives with her, the spinster woman relying on Natsuko’s inheritance for her income but she also acts as Natsuko’s guardian. Still, not wanting her too close she sent her to finishing school in Paris.

Upon her return to England she came out in a lavish ceremony, a mix of Japanese and European custom and began to involve herself in the society of England and the duties of debutantes in this sphere. The two split their time between Natsuko’s London home and Hogsmeade. Natsuko’s aunt the sister of the late General Mountbatton, is deeply protective of Natsuko and wants her to marry well, but relying on Natsuko's inheritence for her own comfort and lifestyle, she comforts herself by grumbling into her teacup and meddling in her romantic life which Natsuko doesn't mind.