She is Master of Flame, Nyx. One of the beautiful warriors from Queen's Blade.
Choose one of the green buttons in the lower left corner to play Rock-Paper-Scissors against Nyx. If you win, you will cause damage to Nyx, and if her HP drops enough her clothes will be destroyed.
If you're lucky, you can sometimes cause a special hit. Each move has a different special hit.
Rock's Critical Hit gives 150% damage.
Scissors will make Nyx Confused. In this state, she cannot win the next round. However, you can't cause another Confused Hit in a row.
Paper will harm Nyx and also restore the player's HP.
Be careful, Nyx can also cause critical hits! The type of outfit she is wearing will determine how strong she is.