Years ago, when the earth was still young, two great powers fought over this planet and its inhabitants. One was a spirit of light and the other of darkness. The one of light was known as Tatsu, The Great Dragon Lord and protector of the mortal world. The other was Goru, The Dark Emperor and Master of the Red Dimension, or Shadow Realm.
For many years their battle waged on, until Tatsu was able to wound Goru hard enough to send him retreating back into his own realm. However, the Dragon Lord himself was also badly wounded in the process and the battle was far from over. It would only be a matter of time the Dark Emperor would regain his strength and return to fight again. Tatsu also knew that he would not be able to survive another battle, therefore, he ventured out from his mountain home o Dragon's Peak to find a human that was brave, strong, and of pure heart to take his place. He found such a man living among the Guardians (people who worshipped the Dragon Lord). His name was Shintaro Hiroshi. Shintaro was found abandoned as an infant and raised by the Guardians. Lord Tatsu bestowed all of his powers to him, thus making him the very first Dragon Warrior.
By the time Goru and his army returned, Shintaro was ready. After a long and exhausting battle, Shintaro was able to cast the Demon Lord back into the Shadow Realm and seal off the gateway. Just before he was banished to his dimension, Goru vowed that he would one day return no matter how long it took him. Tatsu knew that this was possible, for as long as there was even one human with evil in its heart, there was a chance that Goru may be able to return. The Dragon Lord then made a promise to Shintaro that the powers of the Dragon Warrior would not die with him. Instead it would be passed down throughout his generation to every first born that bared the mark of the Dragon.
And so it has been ever since, from first born to first born in the Hiroshi family. All the way down to latest Dragon Warrior, Mika Hiroshi. She's a bit more unique, however, being that she's the first born who is a female. Somehow, every first-born child had been a male until now. Course, Lord Tatsu never directly said that the Dragon Warrior 'had' to be male.
Here's a copy of the poem that tells of Lord Tatsu's promise to Shintaro written in the ancient writing of the Guardians:
A warrior shall rise,
The mark of the Dragon on their side.
Well that's it! If you like,
you can visit both Mika and her best friend Asa Yoshino in their rooms