Lena is the first important character to appear, although she is not introduced by name initially. She is a famous Otome, once extremely skilled and powerful, but chose to give all that up in order to bear a child. She is the original owner of the Blue Sky Sapphire. Wounded during a raid on Windbloom Castle, she sent the baby princess of the Windbloom royal family down a river along with the Blue Sky Sapphire, but was soon after was caught by the forces of Aswad, and was killed. Sergay Wáng, who at the time was a visiting exchange student, observed Lena at the palace and developed a crush on her.

Lena is 16 years old and is the Meister Otome for the King of Windbloom, Bruce Blan Windbloom II, and originally wears a different Meister GEM, the Lofty Crimson Jade. Her Element with the Jade is a bow. She went to school and is good friends with Elliot and Raquel. Lena is afraid of her overwhelming power as an Otome, and avoids materializing whenever possible. After Lena and Bruce rescue Sifr from Kiddo she looks after and protects her, and the two quickly become good friends. Lena uses the alias "Rena Yumemiya". She is called the Monster of Garderobe by her enemies because of her amazing power. Her power overwhelms her GEM during a fight with Schwartz's cyborg, M-9, and the GEM cracks. Lena's new Meister GEM, which is finally capable of keeping up with her ability, is the Blue Sky Sapphire. Her new Element is a crystal spear, the Blue Sky Sphere.