And if the title sounds familiar it might be because Robin Beerbower mentioned this one during the Shout n' Share panel at BEA!
Yoshitaka, who was about to leave his wife, is poisoned by arsenic-laced coffee. His wife, Ayane, is the logical suspect except that she was hundreds of miles away at the time of the murder. The lead detective, Tokyo Police Detective Kusanagi, is immediately smitten with her so his assistant does what her boss has done for years when stymied—she calls upon Professor Manabu Yukawa.
"Higashino has taken the art and craft of mystery writing to a new level of excellence." -Library Journal (starred review)
"Howdunit, rather than whodunit, appears to be the central question of Edgar-finalist Higashino’s brilliant second mystery. [...] While readers of classic mysteries will be delighted with the elegant solution, the book will also appeal to fans of procedurals that carefully develop the relationships among the investigative team members." -Publishers Weekly (starred review)
Kirkus Reviews included it as one of their "10 Hot Crime Novels for Colder Days."