Violence PM (2010)

After witnessing a gang murder, 12 year old Masashi asks his father what he'd do if he were killed by a Yakuza. "Exact vengeance," his father promptly replies. The next day, in an unfortunate turn of fate, Masashi's father is hospitalized with serious injuries, leaving Masashi to fend for himself in a bad and violent part of town. Luckily, he is taken in by a generous family who decides to help him. However, Masashi soon discovers that the father of this family, has a rather bad reputation.