The World of Japanese Dating Apps
digg.com
digg.com
I found the mention of religion a little bit out of place. For the vast majority of people religion has absolutely no connection to dating.
Also, I think there is a fairly clear demarcation between "having fun" dating that you might do in your college days and early twenties and "serious" where you are dating with the intention of marriage and children. Anecdotally, people have fun until they feel it's time to settle down, after which they very quickly find the type of person they want to marry and get married.
"Nearly all of the Japanese dating apps I looked at require male users to pay fees on a monthly basis"
For those curious about blood type personality theory, here's the Wikipedia: https://en.wikipedia.org/wiki/Blood_type_personality_theory