BackgroundCenturies ago, this former pirate had gotten into a disagreement with his sister, Masaki. While trying to look for her, the boy began climbing the branches of a tree that was revealed to be the sleeping Chousin goddess Tsunami. Because Tsunami had been asleep for so long, parts of her had begun to turn into a tree. After waking up, Tsunami detected evidence that the descendants of this man would produce the higher being (kami) that the Chousin were looking for.
Tsunami made a pledge to the man of House Masaki to protect him and his descendants. She provided with him seeds that would grow into "Royal Trees of the Imperial Family." These trees are sapient and powerful beings who bond with Jurai's Royal Family, providing them with great power and long life-spans. They are also the central core of Juraian ships, acting as their 'heart' and computer unit, far more powerful than anything else, thus allowing Jurai to become a superpower.
However, the man, much like some of his descendants, did not want the responsiblity of ruling Jurai, so he intended to push the leadership onto his sister and then run away. Unfortunately for him, Masaki beat him to the punch and took her Royal Treeship on an exploration and ended up colonizing Earth.