Lost Love Murder (2010)

Shuichi Minamida lives comfortably on the proceeds of his father's legacy, but he struggles with the idea that his beautiful wife, Moyako, no longer loves him. One day he confesses his worries to Kotoura, his dentist. Kotoura summons the Akechi detective agency and asks them to investigate his friend's wife, Miyako. Fumiyo Akechi takes the case and begins her investigation. She soon notices that something strange is going on between Miyako and the dentist. This observation leads to a tragic ending which none of those involved could ever imagine.