Yuuki Rio

Yuuki Rio (悠木 莉緒) is one of the main protognists of Visual Novel Mahou Shoujo Fairy Knights, she is also a magical girl known as Lancer Fairy (フェアリーランサー).

Personality
Rio is a polite and smart girl, opposite of Miu

History
At some point in her life, Rio, alongside her best friend, Himemiya Miu, meets the fairies Paruru and Pururu.

They have come from Pixy Palace, a dreamy world of pixies. Pixy Palace is made of right thoughts of humans such as dreams and hopes. Humans receive a power from Pixy Palace to make their dream come true in return.

However, a prince of darkness named Bakdao is born in Pixy Palace. Bakdao plans to destroy Pixy Palace and deprive humans of the power to fulfill their dreams. Paruru and Pururu turn Miu and Rio into legendary warriors "Fairy Knights" because they have the strongest thoughts than anyone, they try to defend the entire planet.

In Fairy Knights Story
Miu and Rio fights daily to protect Earth, in the middle of this conflict, the two girls meet Il Geer, a wily man of the Bakdao Three.

Il Geer finally defeats both of them, but he spared them.

Il Geer analyzes the battles with them in the past, and finds out the week point of their mind; they both have a sense of shame.

Il Geer tries to make the two warriors depraved by the pleasure accompanied by the sense of shame and take their mighty power away.

Miu and Rio gradually succumbs to the pleasure, but they are able to defeat Il Geer in the end.

However, Bakdao appears at the final moments, revealed that he has waited for this moment.

Miu and Rio, whom mighty power are weakend in the previous fight, unable to defends themself, they got easily defeated by Bakdao.

Bakdao corrupts their souls with pleasure, finally turns them into his slave, and the Earth is doomed.

Alternate Reality
In an alternate reality world of Taimanin Asagi ~Kessen Arena~ (a Battle card game by Lilith which crossover with multiple series that developed by Lilith), Miu and Rio also appears as Fairy Knights. They try to fight against the Protagonist, but will got captured and brainwashed by him, and becomes his pawn to fight against the Protagonist's enemies.