Heaven's Island

Satoshi returns to Taketomi Island for the first time in 15 years to take part in his grandmother's 97th birthday "mandala" party, a special celebration that's unique to this island. He re-unites with Miki, his childhood friend but at the same time, as he arrives at his grandmother's house, he is told that she has just passed away.
Satoshi and Miki don't know how to accept this sudden news. But the next day as they read grandmother's diary, they discover that she had always had a special place in her heart for someone else...