I keep reading modern Japanese fiction in the hope that, one day, it will suddenly all make sense; but it hasn’t happened yet. This slim little book is, for the most part, a gentle and achingly tragic tale of a near future that feels all too plausible. Environmental and nuclear catastrophe has led to political isolationism, mass extinction and the reversal of the natural order: the old remain spry and sprightly into extreme old age, while the children suffer from genetic mutations and endemic sickness. We watch an old man struggling to care for his great-grandson, and trying to come to terms with the guilt of an entire generation. It all flows along terribly well until the last pages, when a sudden and utterly unnecessary narrative shift leaves you floundering at the final curtain.