Hanami, a tradition unique to Japan ?

[nova]

why did Japan become so obsessed about cherry trees in the first place, while most other countries did not fall in the same excess ?

I heard a curious explanation about this by a japanese teacher when another student asked regarding that; in many tragic stories of love -sort of Romeo and Juliet type-, the main characters seal their forbidden love by committing suicide together under a cherry tree (while it blooms of course), the cherry tree works as symbolism of their pure love that dies young. Is like the romantic idea that most people have of the roses, it considered beautiful because is associated with a romantic idea, and can also be compared as why not every one likes Ume as much not every one likes other flowers so much in western culture.
Nowadays, seems related with friendship, loyalty and love.
Call it a cultural issue, I don't know if that works for you.