Concrete (2004)

AKA: Konkurito
Directed by: Hiromu Nakamura
Starring: Sosuke Takaoka (Tatsuo), Miki Komori (Misaki),
Country: Japan
Language: Japanese (English Subtitles)
Runtime: 01:29:41
Genres: Gruesome, Sexual-Violence against Women, Based on a True Story, Teen-Oriented, Torture, Captivity-Kidnapping, Domestic Abuse, Scars

Plot – Spoilers:
Tatsuo is contemplating marrying his girlfriend and on the lookout for a better-paying job. He joins the Yakuza and soon even gets to have his own little gang. But being a bit of an asshole, the small crime doesn’t quite do it for Tatsuo and he soon takes to raping girls around town. On one occasion, the rape and torture goes on for weeks and the gang loses all touch with what they’re up to.

Concrete is based on the real case of Junko Furuta, where many people including the bullied parents of some of the gang members were aware of what was going on and on.