Tekkon kinkurîto (2006)

In Treasure Town, life can be both peaceful and violent. This is never truer than for our heroes, Black and White - two street kids who claim to traverse the urban city as if it were their own. But in this town, an undercurrent of evil exists and has its sights set on the pair of brothers, forcing them to engage in battle with an array of old-world Yakuza as well as dangerous assassins vying to rule the decaying metropolis, Treasure Town.