Jimbocho, an area of Tokyo sandwiched between the Kanda River and the Imperial Palace, is a book lover’s dream. Out-of-print novels, vintage cinema posters, essay collections and scholarly tomes line the shelves of its many used bookstores, occasionally spilling out into street carts outside. It’s easy to spend hours strolling its alleys, hunting through the voices from the past.

That hunt is what brought Titus Boeder to the neighborhood one day in the spring of 2004. A London-based dealer in old books who specializes in Far Eastern material, Boeder was perusing what the antiquarian shops had on offer when he happened upon a stack of photographs.

Each measuring 20.3×25.4 centimeters, the monochromatic images depict what look to be a pair of detectives — one perhaps in his 20s, with a well-defined Greek nose; the other, his hair cropped short, carrying the confidence of the senior partner; both wearing trenchcoats over their three-piece suits. They appear to be canvassing working-class neighborhoods in the capital, talking to shop owners, visiting dingy bars and taking drags on cigarettes. The background scenery suggests the shots were captured not too long after the war.