Reira Akaba

The younger sister of Akaba Reiji, dueling in the Junior class of the Maiami Tournament. She is very timid and shy, always carrying a patchwork teddy bear with her, even going as far as hiding behind its face as the crowd cheered.
For most of the series, she is mistaken and referred as a boy due to her masculine clothing until the final Duel against Zarc.
Later, she is chosen by Reiji to be one of the Lancers, stating that Reira is very important for his plans, especially for the fight against Academia.
Reira is actually the adopted daughter of the Akaba family, an orphan whom they found in a war-ravaged city, alone in a house. The Akabas took her in and ran tests on her. From the tests, her new adoptive mother concluded she would be a perfect Duel soldier for them as she had no "sense of self", meaning she would either be able to become a different person or be a mindless puppet following orders.