Based on this chapter I can surmise in Japan student housing for families don't exist. I thought it was just normal that a married student couple could, with luck, get into a family unit. Although more disappointing was the dude getting seemingly displeased that he "needs" to live with his young wife whom he adores very deeply.
If he's worried about knocking her up, just use contraception. Seeing how we suddenly got magic involved in the story, it's 100% certain to exist. Otherwise, in the vast majority of the cases, he's supposed to get intimate with her, and she with him. They love each other to boot, despite it being an arranged marriage, so what's the problem? The publication this is a part of is such that it absolutely forbids merely suggesting a (married) couple could have sex, even if it's not shown?