Gukoroku – Traces of Sin (2016)

Tanaka is going through a tough time trying to support his younger sister Mitsuko, recently arrested and hold up in jail. As an investigative reporter, he immerses himself into a story about a shocking murder case gone cold. The “perfect” family—successful businessman, beautiful wife and adorable child—was brutally murdered a year ago and the case remains unsolved. Tanaka interviews their friends and acquaintances, and as stories of their true nature unfold, he begins to discover that the family was not as ideal as believed. The interviewees themselves unveil their own hidden natures, revealing a disturbing portrait of social elitism.

Gukôroku (original title)