The film is based on a novel, which itself is inspired by a real world case: Mitsubishi Fuso recall cover-up scandal, occurred in early 2002 but was not discovered until 2004.
The age gap between Noji-kun's actor (Bando Ryota) and Sawa-chan's actress (Takeyama Ruka) is huge (9 years). They are very good though, their interactions are so natural, I never thought that they have such huge age gap.