The two were inseparable. You wouldn't find one with out the other. The two siblings were the best of friends, and, even though he was a year older then she was, the two had bonded in a way that nobody else could've done, but that had ended.
She was sent to al boarding school, and he was sent to a academy that worked on Martial Arts skills. The two would be finally separated. When they found out, they were disappointed at first, but they realized what they had to do, so they went their separate ways.
Their parents had a plan for the two, but fate went in another direction.