In Tokyo, 16-year-old Nao has decided there's only one escape from her aching loneliness and her classmates' bullying. But before she ends it all, Nao first plans to document the life of her great grandmother, a Buddhist nun who's lived more than a century. Across the Pacific, we meet Ruth, a novelist living on a remote island who discovers a collection of artifacts washed ashore in a Hello Kitty lunchbox. As the mystery of its contents unfolds, Ruth is pulled into the past, into Nao's drama and her unknown fate, and forward into her own future.