Umiko Wada never set out to be a private detective, let alone become the one-woman operation behind the Kodaka Detective Agency. But so it has turned out, thanks to the death of her former boss, Kazuto Kodaka, in mysterious circumstances.
Keen to avoid a similar fate, Wada chooses the cases she takes very carefully. A businessman who wants her to track down his estranged son offers what appears to be a straightforward assignment. Soon she finds herself pulled into a labyrinthine conspiracy with links to a twenty-seven-year-old investigation by her late employer and to the chaos and trauma of the dying days of the Second World War.