Shirou is a simulacrum, in other words, a creature made to resemble something else, in this case ordinary felines. Rieka had ordered the creation of these to further experiment with her theories. All Shirou has known is the life of a lab rat. That is, until the day he and a couple others managed to break free from their prisons during a strike, in which he later met Aspen. The two shared the same hatred to the Mages, and thus shared the same goal, so they allied from then on.
Shirou is a generally grumpy, tired, and occasionally apathetic cat who’s trying to adjust to life outside alchemy labs. Many “outside” things confuse him, which frustrates him, especially when it’s pointed out. Due to his lack of experience, he might appear naive, but his sceptical nature keeps him from doing anything too stupid.
He suffers from cleithrophobia; the fear of being trapped, due to his past. He hates physical restraints, locked rooms, or being unable to freely leave an area. The closer the resemblance to his old life, the more anxious he gets.
