From No Game No Life. Cosplayer is natsu.
The granddaughter of the former king of Imanity. After the king's death, she gambled to become the next queen of the country. Although she was forced by the pledges to fall in love with Sora after losing a game to him in Episode 02, she has since developed feelings for him despite denying these feelings on a consistent basis. In the short story that comes with Blu-ray DVD, Steph actually lost a bit of her mind when she was defeated by Sora again and again. Stephanie is expressive and emotional, wearing her heart on her sleeve to the point where she cannot hide her emotions during a poker game. She loved her grandfather dearly and is angered when people call her grandfather a fool. She fell in love with Sora due to the pledges forcing her to, and she often has violent outbursts to try to break free of it. However, Jibril later stated that the pledge did not specify a time frame, and so should have worn off, meaning Stephanie had probably truly fallen for Sora. She loves her kingdom and world and believes in the potential of Imanity (humans). (no-game-no-life.wikia.com)