The story opens with the crushing weight of the debt. The couple is desperate, and the husband often feels emasculated by his inability to provide or protect the family.
The wife "sacrificing" her dignity to save her husband's life or future.
Use multiple save slots before major decisions or at the start of each in-game week so you can backtrack if you miss a deadline.
If you're interested in writing a piece like this, consider the following:
Your choices—and often your success or failure in paying back the debt—determine which ending you receive. "NTR" (Netorare) elements specifically suggest that the story will branch based on how much the "wife" character interacts with other NPCs. Tips for Progressing