A long time ago it was one of the most important ceremony. So they couldn't directly see their lovers before they got married. Japanese women had to marriage for their family a long time ago. Most of Western people can love freer than Japanese people though I don't know about Western love that well. Both Japanese love and Western love aren't only sex.
Love is sex and many things , that is to say , love needs important invisible things.
In Japan the first-born son often has to succeed his house. So an arranged marriage is also a Japanese love style. I wonder why American people don't exercise stricter control over drugs or guns. Of course there are a few people who have guns and drugs in Japan , too. I think if parents divorced , their children feel lonely.