It was at least a hundred years ago, perhaps a half century more or so.
At this point Koishi had entered the ranks of the guard. A new recruit. At that time, with the mental scars of a century of isolation already upon her. In this day and age she still wasn't very well known. She was just a faceless, identity less member of the guard, taking orders. As it was now, all she did was spend her time cleaning and training. It was a thankless job but she was happy fulfilling it. What was more fulfilling than finally doing things again? It brought her a sense of actually being functional.
She had on that day spent the morning working on cleaning windows and the afternoon working on flooring. Usually, her squadmates would slack off their work, because to them it wasn't right for members of the guard to be doing maid work. Koishi, however didn't mind. She was hardworking and knew what needed to be done, regardless of pride. Even in her inexperience, she understood that it was necessary for someone to clean. So, even if her squadmates did not, she did her best.
It was evening now, and Koishi finally had some time to train on her hands. Having just washed plates and cleaned up, she meandered he way into the training grounds to finally begin. However, she wandered past these grounds and a little off the area. She didn't want one of her friends to run into her while she was training or get too close. She still was pretty bad at her range and needed more control. She couldn't train on dummies either, not with her abilities.
She wandered until she found something living. A squirrel. Perfect. She focused a bit, closing her eyes, targeting the simple mind before her. Some may say that it was easier than a human, but it was actually much harder. Small animals had small minds. Everything was cramped and it was easy to overwhelm them. It was perfect for her control training. She felt herself enter in, and tapped into the squirrel's mental defense systems, setting them so that it was calmer and friendlier. However, she underestimated her strength and instead the squirrel screeched as if in pain, running away.
Koishi opened her eyes, sighing. It was still difficult... but she must continue.