Birth and Exaltation:  Raikou's full name is Tepet Li Shen Raikou, and was born in RY 767 to two unknown parents during Calibration.  He was left to die on the streets of the Imperial City because of this.  However, a servant of House Tepet found the child and took him into his master's home, being a compassionate man.  The master of the household allowed his servant to raise child and arranged for the servant to become the legal guardian.  This was a gesture of kindness towards the old servant, a childless widower who had loyally served House Tepet his entire life, then acting as the major domo for the manse.

Raikou was taught by his surrogate father in the ways of managing households, though the child's temperment was more aggressive than one would expect, and always fought with the household's 'favored' children.  In return, the Dynastic children taunted him about his low birth and how he would never become Exalted, for Raikou had obviously led a less-than-pious past life.  Imagine their surprise when, on his thirteenth birthday, Raikou Exalted during his latest fight with his life-long rival and wrecked the kitchen with the elemental fury of his anima banner. 

Of course, Tepet Vergus Xialou Shenshiro also Exalted during that fight...  

And then of course Shenshiro's parents formally adopted Raikou into the House to provide an education worthy of a Prince of the Earth....

Naturally, the two have been bitter rivals ever since the day they Exalted.

Education and Service: Owing to familial connections, the troublesome rivals were exiled to the House of Ancient Stone for their secondary schooling, having earned a reputation as 'problem children' in primary school.  There was an incident near the end of their primary schooling where Shenshiro and Raikou rampaged through the halls with anima banners flaring as they fought.  They were pulled apart by the headmaster, a stern and ancient member of House Ragara.

In the House of Ancient Stone, they were better, owing primarily to the schedule of exhaustive farmwork prior to each day's studies.  However, the two did keep their rivalry going, each trying to outdo the other in studies and manual labor.  They were noted as being some of the best students to graduate from their class, only due to their constant need to best each other.  It was during this period that it was noted that both Exalted seemed to have an innate mastery of their essence that few at their age had.

When they graduated, it was time for them to earn their stripes.  They were tossed into the fire by their elders; enlisted in the Red Piss Legion under the commanding presence of Tepet Ejava.  While both proved to be capable of command, their rivalry cost them much.  Eventually they were discharged from the Legion after four years of service.  Shenshiro returned to the open arms of his parents, while Raikou was exiled to the East in disgrace.

Exile:  Because his surrogate father had died while he was in the House of Ancient Stone, Raikou's adoptive parents found no reason to continue doing him favors beyond a modest (for a Dynast) stipend.  When an Outcaste attacked him on the road to Greyfalls, he killed the backwater Terrestrial and claimed the magnificent weapons and armor for himself, giving them names and performing a prayer to Mela thanking her for the gifts she had granted her humble servant.

Except things got worse.  His brother had convinced the house elders that Raikou was guilty of horrible things, and he was disowned by a House that could scarcely afford to disown a Prince of the Earth.  Stipped of everything House Tepet gave him, Raikou was cast out.  He took the name of the man who was more family to him than any other and worked on rebuilding his life and plotting how best to ruin his enemies.

Goals:  Raikou wants nothing more to utterly destroy his brother and the house that disowned him.

Notes:  Yes, Raikou has the actual Bad Luck flaw to reflect that he was born during Calibration.