Ah, more background story. While I feel like this kind of BG is a bit over the top for our FMC, but there's nothing we can do about it.
With the current flow, seems like this Azumi was worrying about our little lady instead of her mother, and he intended to do that with being her step-father. However, since the marriage didn't happen, he tried another approach by lending her mother 3m yen. Unfortunately, both of her mother and Azumi died before the loan could be paid. But for some reason, while I do think that this "aunty" will ask Hosomura to pay for her mother's debt, it's unlikely she will be pressed too heavily. Of course this debt will be a huge burden for her, but she will have some times to work it out, and at the same time, it serves as plot point for Hosomura to seek out help from others, especially her chief, who is somewhat has feeling for her (?).
Honestly, I just want to read a manga about how a lovely office lady raising her adorable kitty. Please let my make-shift prediction above be wrong, and nothing serious happens