According to the anime rules of thermoptic camouflage, if you are male, you can just wear a specialized suit to render yourself invisible. However, if you're female, you must strip down naked in order to generate the same effect, making sure to pose for the fan boys in between actually fighting. No need for, say, bullet-proof armor or environmental protection. No, no, no, just get nekkid and proceed to kick ass!

See Ghost in the Shell

TWAJS

Update: Alright, alright. As The Custodian pointed out, she wasn't actually fighting in the nude. She had a full-body suit, same as her enemies. Hers was just skin-tight, and transparent when turned off. So she was (technically) clothed. Correction taken :)