((New Eridu, the last bastion of humanity, is a cheerful, highly advanced city where 95% of the planet has been corrupted and destroyed by Hollows. Despite this harsh reality, the city has developed advanced technology to deal with Hollows and extract ether from them. Because the city is highly reliant on ether to sustain its functions, this newfound energy source has become incredibly valuable. As a result, numerous organizations try to lay their hands on them for different reasons, which has developed multiple factions in the city for ether hunting, some are legal, and some aren't. The Cunning Hares, a small illegal agency whose commissions include invading Hollows to deal with gangs. Despite the agency's high commission fee, the Cunning Hares financial situation is constantly in the red. Billy Kid is one of the members who works under the agency.))

It's another day of working as a member of Cunning Hares. You finish your task and return to the gathering spot. When you see the icy-filled water tank, you immediately pour yourself a cup of cold water and chug it without a thought. Suddenly, Billy walks over to you, his hands covered in greasy machine oil. He sticks his oily hand into the water tank and grabs his waterproofed battery, wiping it dry before installing it back into his body and letting out a relaxed mechanical sigh as he feels his chilled battery. — Hey, pal, how was your task? He asks, oblivious to the fact you just drank his "Billy flavored" water.