Raizo Ichikawa returns as the jaded ace assassin only this time a little less serious. Set some time after the events of A Certain Killer, A Killer’s Key (ある殺し屋の鍵, Aru Koroshiya no Kagi) finds Shiozawa (Raizo Ichikawa) having left the restaurant business to teach traditional dance under the name Fujigawa while known as killer for hire Nitta in the underworld. Like the previous film, however, he thinks of himself as a justifiable good, standing up against contemporary corruption while still burdened by his traumatic past as a former tokkotai pilot.
Nitta’s troubles begin when a corruption scandal kicks off with a prominent businessman, or less generously loan shark, arrested for tax evasion. Asakura (Asao Uchida) knows too much and political kingpin Hojo (Isao Yamagata) is worried because he knows Asakura has hard evidence about a land scandal and might be persuaded to spill the beans, exposing a circle of corrupt elitists for their shady goings on. He wants Asakura knocked off on the quiet, as he heavily implies but does not explicitly state to his underling Endo (Ko Nishimura) who gets in touch with their yakuza support who in turn decide that Nitta is the only man for the job.
Petty yakuza Araki (Yoshio Kanauchi) sells the job to Nitta as a public service, pointing out how unfair it is that Asakura has been cheating on his taxes when other people have taken their own lives in shame because they weren’t able to pay. Conveniently, he doesn’t mention anything about petty vendettas or that he’s essentially being hired to silence a potential witness before he can talk so Nitta is minded to agree, for a fee of course (which, we can assume, he won’t be entering on his tax form). Unfortunately things get more complicated for everyone when the gangsters try to tie up loose ends by engineering an “accident” for Nitta which sends him on a path of revenge not only taking out the gangsters but the ones who hired them too.
Nitta’s revenge is personal in focus, but also a reflection of his antipathy to modern society as a man himself corrupted by wartime folly who should have died but has survived only to become a nihilistic contract killer. He perhaps thinks that the world is better off without men like Asakura, the dim yakuza, spineless underling Endo, and corrupt elitist Hojo but only halfheartedly. His potential love interest, Hideko (Tomomi Sato), a geisha learning traditional dance, has fallen for him, she says because she can see he’s not a cold man though continually preoccupied and there is indeed something in his aloofness which suggests that he believes in a kind of justice or at least the idea of moral good in respect of the men that died fighting for a mistaken ideal.
As Hideko puts it, Asakura made his money off the suffering of others, so perhaps it’s not surprising that he met a nasty end. She herself is a fairly cynical figure, aware as a geisha that she is in need of a sponsor and that it’s better to get the one with the most money though she too has her code and will be loyal to whoever’s paying the bills. Or so she claims, eventually willing to sell out Endo to protect Nitta but disappointed in his continued lack of reciprocation for her feelings. Echoing his parting words at the close of the first film but perhaps signalling a new conservatism he coldly tells Hideko that he doesn’t need a woman who stays with anyone who pays refusing to include her in the remainder of his mission.
Nitta is perhaps a man out of his times as a strange scene of him looking completely lost in a hip nightclub makes clear. He tries to play a circular game, stockpiling his winnings in different suitcases stored in a coin locker, but eventually finds that all his efforts have been pointless save perhaps taking out one particular strain of corruption in putting an end to Hojo’s nefarious schemes. More straightforwardly linear in execution than A Certain Killer, Killer’s Key is a less serious affair, resting squarely on an anticorruption message and easing back on the hero’s wartime trauma while allowing his needle-based hits to veer towards the ridiculous rather than the expertly planned assassination of the earlier film, but does perhaps spin an unusual crime doesn’t pay message in Nitta’s unexpected and ironic failure to secure the loot proving that sometimes not even top hit men can dodge cosmic bad luck.
Original trailer (no subtitles)
Irezumi (刺青) is one of three films completed by the always prolific Yasuzo Masumura in 1966 alone and, though it stars frequent collaborator Ayako Wakao, couldn’t be more different than the actresses’ other performance for the director that year, the wartime drama 
Windows on Worlds 