In a 19th March 2008 article entitled "Oldman to join cast of 'Rain Fall'" published in show-business trade paper 'Variety', Japanese producer Satoru Iseki "said the film will have the distinction of being the first Japanese movie to use a completion bond."
At one point in the movie, a "Smiley" face image is seen on a computer screen. Star Gary Oldman later portrayed the character of George Smiley in John le Carré's Tinker Tailor Soldier Spy (2011) which was made and released around a couple of years later.
The film was made and released about seven years after its source novel "A Clean Kill in Tokyo" by source novelist Barry Eisler, the book having being previously published as the film's title as "Rain Fall", it being first published in the year of 2002.
The movie's source "Rain Fall" novel (aka "A Clean Kill in Tokyo") was the first of Barry Eisler books to feature the character of John Rain.
Star Gary Oldman later portrayed a similar espionage section chief character in Ariel Vromen's spy thriller Criminal (2016).