With revenge etched on his mind, following the brutal murder of his wife, a brilliant Japanese doctor comes up with an outrageous, nearly perfect assassination plan. Now, to make the killer pay in blood and rue the day he was born, the pained hermit trains meth-addict Mayumi to become a lethal, pitiless assassin. But that's the easy part. The hard part involves entering the sadist's heavily fortified underground lair. However, there's a catch. What will Mayumi use as a weapon?
—Nick Riganas