When you think real hard, it almost blows my mind at the theory that Kagome or Miroku's family ends up becoming Kagome' (present) ancestor. Why the traditions are well kept, why the Higurashi family has been tasked to keep the god tree, the well and the shrine after all those years.
Why they kept their tradition was because Kagome would eventually tell them that she came from the future, and in order for the future to be saved, the well, the God Tree and the creation of a shrine within that village.
Haha... The last time I read this series was when I was 12-13 years old. Man, I am old.