Circumstances for the repayment
"Father...are you sure that this...maker woman didn't ask for anything in return at the time?," Zhen Long asked. "It had been a really long time since you met her and it's possible you paid her back already."
Zhen Shi shook his head almost immediately at Zhen Long's statement.
"I know the debt hasn't been paid yet because, I remember the one really weird, really specific thing she said would be proof that everything had been settled," Zhen Shi explained.
"Which would be..."
"Cubed caramels."
"What?"
"She said, and I might be paraphrasing a bit, that the moment I see a bag of cubed caramels with her shop's emblem on it, that is the sign that everything has been settled."
All seven of Zhen Shi's sons and their spouses just looked absolutely bewildered at this statement. Partially because how nonsensical such a sign would be, but mostly because they had no idea what the fuck caramel was.