A Tale for the Time Being by Ruth Ozeki, review American-Japanese author Ruth Ozeki's third novel opens with a bad pun by a suicidal Tokyo schoolgirl: "My name is Nao, and I am a time being... someone who lives in time, and that means you, and me, and everyone of us who is, or was, or ever will be," she begins, addressing the unknown reader of her diary. Together we're making magic, at least for the time being. Nao (pronounced "now," another signpost to the novel's main preoccupation: the nature of time) has recently moved back to Japan from America where her father was sacked from his job as a computer programmer. Shunned by a society in which they no longer feel at home, first her father and then Nao contemplate ending their own lives. Nao pens her thoughts in a "diary of my last days on Earth." More than a decade later, the diary, wrapped in a freezer bag, is washed ashore in British Columbia where it's discovered by Ruth, an author, based on Ozeki herself. Trying to discover if the schoolgirl killed herself or died in the 2011 tsunami, Ruth and her husband, Oliver, begin an increasingly desperate search. Ozeki uses the relationship between author and schoolgirl to conflate past with present and fact with fiction, and A Tale for the Time Being - with translation footnotes, six appendices, a bibliography and quotations from Japanese Zen masters - is a metafiction wrestling with grand themes. Ruth and her husband contemplate quantum mechanics and Schrödinger's cat. Nao and her father struggle with the modern notion that, thanks to an internet which catalogues mistakes, our past is ever present. But the book is at its strongest not in these ambitious philosophical explorations, which can at times feel unsubtle, but in its quiet detailing of the love and pain of family life - in the moving depiction of the small hurts and comforts of Ruth's marriage and in the painful portrait of the tortured relationship between Nao and her depressive father. What binds it all together is the voice of Nao, who manages to be both a convincingly self-obsessed Tokyo teenager and a sympathetic and engaging narrator. And as she navigates the end of her childhood (and, perhaps, her life) through a mist of cultural confusion, she provides us with a compelling coming-of-age story. A Tale for the Time Being Ruth Ozeki Canongate, £20, 400pp