Ok so warning
Don't read if you don't like the idea of maybe getting spoiled, as someone might make a guess that turns out to be right.
I don't mean this to influence the author in any way, either. I assume and hope he won't read this. From what I gather, whatever ideas he already has wouldn't be swayed anyways, and that's something I respect and encourage.
Oh and I don't remember the name of that AnthroPC so I'll stick to "female" or "anime-themed."
Assuming we already know that AnthroPC's owner, directly or indirectly. Who might she be? We know it's a she, but in QC's world that's not very limiting.
My own theory, considering the tendencies I perceive with my own subjective mind? Marten's ex.
Don't remember her name. Sara, maybe. She showed up most briefly (a single strip) a long while ago, well before the #500+ events that led to Marten and Dora getting together. Must've been around strip 250 or so, but this is a very gross approximation.
What little we know of her, the only time we saw her she was apparently living in the city. Close enough to Coffee of Doom to swing by, and thus close enough to Marten's.
QC has shown a tendency for such "oddities of fate" before, and it would certainly make for a good bit of drama.
I cast my vote for this sudden (perhaps accurate) thought of mine.
What do you say?