Sex anywhere in the world doesn't equate to love, it's a natural instinctsex in Japan doesnt equate to love there (from what i can tell)

It is very typical of Asia not only Japan, go to China, Taiwan, even Korea is no different, culture is culture and the more you learn the more you will understand, that family bonding is more important than sex. Sex is a basic function of survival and instinct, so if your partner is more active than the other, they will eventually stray.
Vows are not stronger than instincts ask any wise man or priest

