The Devotion of Suspect X by Keigo Higashino

At first glance, it seems that this novel follows a well-worn story line, in which a wife, Yasuko, murders her abusive ex-husband, in this case with the help of her daughter, and then the neighbor, Ishigami, overhearing what happens, steps in to help dispose of the body. Yasuko is simply trying to live an honest life with her daughter. The neighbor, a math teacher in a nearby school, has a secret crush on Yasuko.  All three are then bound together to try to conceal their involvement in the murder from the authorities. Maybe ho-hum?

But then it gets really good. Ishigami is not a typical school teacher; he is a genius whose focus is on saving the woman he loves.  Somehow, he disposes of the body, plants doubts in the minds of the police, creates alibis, and as a result, he retrospectively turns an unplanned murder into the perfect crime.

The persistence of the police and their constant questioning of the events lead to the gradual unveiling of misinformation and false trails, all of which are directed by Ishigami. In the end, it is only the persistence of physics genius, Manubu Yukawa, an old friend of Ishigami whom he hasn't seen in 20 years, that forces Ishigami into playing his final hand. 

The Devotion of Suspect X is well plotted, and for once I was completely caught out by the unfolding of the plot towards the end, and the disturbing and unforeseen lengths that Ishigami has gone to, to protect his great love.
Initially, it was a bit difficult because it entailed understanding a society with different mores while following the story and the characters' actions. I soon was able to comprehend many of the actions and enjoy experiencing a different playing field. It definitely was well worth it and I truly enjoyed the mental games of the players.

CAS