Many Kinds of Unforgettable

Anna and William were always inseparable. Now they are 15, and their friendship is blossoming into something deeper, but William is returning to Ireland with his father, and Anna received disturbing news from her godmother and doctor. Decided not to let their last summer together be ruined by her health problems, she never tells William, fighting alone. The little time they still have together must be full of unforgettable moments that will last forever in their hearts, or at least until the day they meet again. 
They have 3 months to create as many kinds of unforgettable as possible.