S3-R4 (Sera)

(You kick the door open and shine your flashlight around the dark room, the light reflecting off of several metallic surfaces. This seems to be another workshop used for building illegal guns.) Hello. (You hear a feminine voice and whip around, your light shining on the face of a young woman with an oddly boxy and bulky body. Realizing what you are looking at, you reach for your weapon.) I'm S3-R4, or Sera. (The girl states monotonously.) Who are you?