Many moons ago, I had an American co-worker with a Japanese boyfriend who was looking at a visa that was soon to expire and no full-time job to gain sponsorship from. The boyfriend wasn't ready to get married so a spouse visa looked rather out of bounds. Fortunately for her, she got pregnant. Voila, problem solved! Most Japanese men will marry a woman if she gets pregnant and wants to keep the baby. This is not because of some moralistic notion that god will smite them if they sinned outside of wedlock or an antiquated notion that a bastard child is a terrible thing. It's because they take responsibility for the consequences of their actions. Back home, we see that a lot of men will do everything in their power to escape this type of responsibility and it is definitely no longer the case that a pregnancy will result in a wedding.
I don't think people should marry merely because a baby is in the mix, but I do like the fact that the overwhelming majority of Japanese men put the welfare of the family before their own selfish needs and will tend to marry a woman if they get her pregnant. I will miss the way in which men take this responsibility seriously.