@OniBarubary - I mean, I doubt it's that much different than the rest of the world. Tbh, marrying your "highschool sweetheart" is, in MY opinion, an unnecessary risk. Whether it's my anecdotal perspective or available stats, very rarely do I ever see they ever work out. My cousin that was married for 13 years and had three kids with his wife just got divorced because they had problems and she was cheating on him.
@OniBarubary Apparently a lot of highschool relationships used to end up in marriage in Japan because of pressure from relatives, but sadly a lot of the time they stop loving each other but they don't get a divorce cause it's not normal there. So a lot of the time they cheat. That is also why there was a population problem.