It’s an eroge (complete with gameplay) based on Ragnarok Online.
THIS POST CONTAINS ADULT MATERIAL! IF YOU ARE UNDER 18 OR THE LEGAL AGE OF YOUR COUNTRY THEN LELOUCH VI BRITANNIA COMMANDS YOU NOT TO CONTINUE!
I found this on HF so credit goes to valkupo who credits fuckfuck.
In this game you play as either an archer or a mage and your task is to shoot down enemies while at the same destroying piece by piece of a certain RO’s girl clothing. The game system resembles (gasp) Ragnarok Online. You can level up your character, your skill, and buy items to heal your HP and SP. If you’re playing the mage then you control with mouse while Archer controls with keyboard.