One day, when I was performing daily maintenance on the Colossus, the Fireflies suddenly got restless. I went to them and heard muffled footsteps, followed by the faint sound of mechanical parts grinding together. What appeared before me was... a robot of some sort? Then I quickly came to my senses and realized that it was probably a dynamic mech suit.
After that, the timorous voice of a girl came from inside. The voice sounded a bit strange because it was confined within the helmet. "Is this %s's Colossus? I'm Ciel, tech personnel of the Illumina Federation. Don't be afraid, this dynamic mecha was made by me."
Ciel? Ciel! That's when I remembered. She was one of my juniors and was nicknamed the "Genius Girl Engineer." That she was, seeing as how she was the one who beat me in that year's design competition and took the championship from me...
—Vice

Ah, should I call you Navigator or %s? I'm Ciel, tech personnel of the Illumina Federation. I'm currently in charge of... tunnel excavation.
I know what you're wondering. Why would I be assigned to such a task, right? It's mainly because of my mecha. According to Tech Officer Gronru, this mecha is very suitable for it, and I'd be able to test the practicality of my design, so I took this job. After all, I was the one who designed, assembled and commissioned this mecha, and this is the second one of its kind. Speaking of which, you may notice that the leg armor doesn't match the rest of the suit. It is, in fact, a leftover piece of my first dynamic mecha. That experiment failed and this leg piece is the only thing left of it. I've been wearing it ever since as a reminder to myself of that fiasco.

Many people in Illumina call me the "Genius Girl Engineer." But I was just introduced to it earlier than others. My parents were quite strict with me. They were just common laborers, but my grandfather was an outstanding engineer.
I have no impression of my grandfather and everything I know about him comes from others. That set of conceptual designs is the only thing that remains of his talent. It conceptualizes a dynamic mech unit that's easy to operate, is incredibly reliable, and can adapt to all environments. Despite fully understanding its structure now, every time I look at it, I'm still amazed by the ingenuity of its design. This design is the origin of my nickname. According to my parents, when I was a child, I claimed that I would one day make Grandpa's design a reality. They believed then that I was a genius and continuously nurtured me in this regard. And I worked hard to not let them down.
I wonder if my fate is intertwined with my grandfather's design. It has laid my life's purpose before me, and will accompany forever...

Have you ever accomplished something in one go? Everyone may have had such an experience, me for instance.
When I graduated from school and started receiving guidance from Tech Officer Gronru, I became preoccupied with the thought of actually creating the mech in the blueprint. Just like others say, I was young and fearless back then, and I had unlimited energy and inspiration. I resolved technical issues like they were nothing and in the end it took me less than a year to make the mecha that I'd thought would take my entire life!
However, things went south when I left to participate in a group activity and forgot to turn off the power of a component I'd been testing, which resulted in an accident. When I ran back to the nearly collapsed lab, I couldn't do anything but watch my dynamic mecha being smashed into smithereens. I ended up injuring my legs trying to salvage this leg armor... I had to stay in bed for a year before I recovered. But afterwards, I was unable to successfully create the mech unit again even using the same blueprint. The one I'm using isn't nearly as powerful as the original suit, which this leg piece was part of.
Thus, whenever I look at it, I'm reminded of the devastating end of my old mecha and can't forgive myself.

During the year I was stuck in bed... My parents took very good care of me, but I could detect a hint of disappointment in their eyes and it pierced my heart like a nail. That's why I put on this leg armor and never remove it. It's the only way I can sleep at ease and not think about their disappointment all the time.
Maybe it was that, or my year of rest... either way, I changed. Even though I still try my best to reproduce the damaged dynamic mecha I lost, and still have the tendency to lose myself in drawings and knowledge, I think from time to time that if I hadn't discovered the blueprint and hadn't been viewed by my parents as a genius, I wouldn't have had to study all the time in school and perhaps... I'd have been able to make some friends.
Ah. But it's wrong to think that way. I must be too tired, like a jammed machine acting uncharacteristically.
Yes. That must be it.