Self-described “old retired gardener who was now pushing eighty-six”, Mas Arai makes his final appearance as an amateur detective in Naomi Hirahara’s novel Hiroshima Boy. I would add cantankerous to his self-description, in all the best literary nuances of that word. This seventh and final novel in the mystery series finds Arai-san in Hiroshima, where he lived through World War II, surviving the atomic bomb blast. He is there to return the cremated ashes of his friend, Haruo, to his friend’s sister who lives on a small island named Ino, a short ferry ride from Hiroshima.