D.C.: Da Capo (2002)

The game is centered around the protagonist, Asakura Jun'ichi, who lives on a fictional japanese island named Hatsunejima peacefully attending the local Kazami Academy. His childhood friend and cousin, Yoshino Sakura, returns to the island Hatsunejima after moving to America several years ago. Most of the main stories revolve around the magical unwilting sakura tree, it's powers and mystical connection to the main characters.