CKTK-049 (usually shortened to CK or "Seekay," among other nicknames) is a military android produced to replace human soldiers, designed to be easier to recover and repair than meatier creatures, but also more resistant to psychological trauma. That said, she and her fellow robo-soldiers are still quite human-like in terms of emotions and personalities, despite having a few "mechanical" quirks and mannerisms. However, right before she and others like her were deployed, an unforeseeable event caused people the world over to lose the will to fight, ultimately leading to world peace. Due to their sentience it would be unethical to decommission the androids, so they now are adapting to civilian life and pursuing other interests, whatever form that may take

FAQ:
"why make sentient military androids?"
-drone-like military robots were developed at first, but due to their ghastly performance in simulations it was decided that something that could take a life should also have a conscience

"Why is she so feminine?"
-Most soldiers are men, so it was thought that they would be less willing to fire on (depending on one's taste) an attractive woman

"...Really?"
-The engineers may have gotten a little bit carried away in a few places, but the size of the legs gives this model a lower center of mass, which aids stability, and there are low-powered sensors concealed within the radar domes on the chest. Such features had a surprising effect on morale, so the design was kept

"Okay, but high heels? seriously?"
-With highly modular and modifiable androids integrating into society, it was inevitable that more fashionable body parts would be developed, just like the clothes and accessories that humans use. Rest assured that the androids did not, in fact, prance around the battlefield in such dainty little shoes. No further appearance-related questions, please!