From my research, I have drawn the conclusion that Otherkin refers to having a deep spiritual connection to something nonhuman and/or believing to have been one's kintype in a past life.
I'm not going to go into my specific beliefs on reincarnation and such, because that's not the point, but I will say that reincarnating to a different species is entirely possible within them.
I am not a very religious person, but I am a very spiritual person. I have always felt a strong connection to felines of all sorts, but specifically domestic cats. I seem to understand them much better than I understand humans [but that just could be my Autism, who knows], and I feel much more at ease with them. One of my spirit guides is in fact a domestic cat, however he is definitely a different entity than myself. Anyways, due to these reasons I find it very plausible that I might have been a cat in one of my previous life cycles, but I'm not certain on that, and I would be okay to find it was false.
Does that make me Otherkin? Or just someone who is spiritually connected to cats?
I also believe there is a possibility I may have even been a bakeneko, but I don't know for certain if those are even real, I just really connect with them. I don't believe in any of that "fictional stuff exists in other universes" bullshit, but I think that there is about an equal chance of mythical creatures existing, or having existed at some point, even in a form different than our human fiction depicts them, or not existing at all.
I'm just confused upon whether or not I would consider myself kin.