The man in the traditional kimono is having difficulty with the breasts. The weight of the belly strains his back. Simply walking around the room—a party room in a Tokyo condo building—is more like lumbering. Lying down and getting up again is a struggle. The rest of the men in the Ikumen class laugh as he tries to adjust to the new reality. But then we all have to try on the pregnancy suit ourselves, and one by one, we come to the same conclusion: It’s hard to be a woman.

The class is sort of like the prenatal ones I attended when my wife was pregnant—except that none of my classmates is actually a father or father-to-be. Some of them aren’t even dating. Many of them will list their attendance in this class on their dating profiles with the aim of attracting a partner. The young women they’re hoping to interest want to see some fatherhood credentials up front.

Ikumen is a portmanteau of the Japanese word ikuji—meaning “child-rearing”—and the English word men. Though the term has been around for years, the divide between work and home in Japan remains nearly absolute. Mothers still tend to shoulder almost all domestic responsibilities—an imbalance that can be miserable, as Masako Ishii-Kuntz, a sociology professor, hears wherever she goes. “I just gave a talk this morning, and my audience [was] all younger mothers,” she told me in her office at Ochanomizu University. “Many of them were talking about ‘Oh, my husband is just simply not interested in housework or child care.’ That’s not rare at all.”