In a world where robots and mechas not only live alongside humans, but can also reproduce and age like them, a robot family of three finds themselves adopting a human baby after a sting operation gone wrong results in her parents being killed. Fast forward years later, Heather and her adoptive sister LouLou are part time vigilantes in the city of Machina and part-time civilians as well. It can be hard to balance a life of both thrill and normalcy, especially when you can't confide your side activities to anyone, but when its a disaster far beyond what the local police can handle, some days, you just have to take matters in your own hands/servos before they get any worse.