Are we going to find out in the future that Hikaru and her dad has some kind of disease that lowers their IQ when they fall in love or something.
Debt sucks but to divorce someone over that and making them become a single parent? I don't know about that.
if you're in debt. Those you owed will make your wife pay for your debt too if there's any link between them. And since the father is basically useless with making money now. All the work would lie on his wife. But if he divorced her, his debt only belong to him. And the creditor won't come to his wife to get money. He will suffer alone. But if he still with her, she will have to work two people job to pay for his debt. At least if they are divorced, her money would be priority to pay for their essential need and their kid future. Not on his debt. Now he only need to suffer alone.