Shinju by Laura Rowland, 367 pages

It is January 1689 in Edo, the city that would one day become Tokyo. The bodies of a young man and a beautiful noblewoman, bound together, are dragged from the murky Sumida River: a typical shinju, a ritual double suicide committed by a pair of star-crossed lovers.
But when Sano, a tutor, a samurai, and now a reluctant police officer, begins a routine investigation, he comes to suspect murder. And as he unravels the twisted story behind these deaths, he stumbles upon a trail of deceit and assassination that threatens the very underpinnings of the shogun's Japan.
Shinju is a suspenseful, page-turning journey through the seductive world of medieval Japanese culture, politics, and sex. Filled with exceptional detail and color reminiscent of James Clavell, informed by the sort of investigatory suspense that inspired Gorky Park, Shinju merges breathtaking historical fiction with a first-rate detective tale.