While the word intelligence may not be the first thing that comes to mind for a movie like Kate, a ticking-clock action-thriller about a lone wolf assassin with 24 hours to live, there are still a few wise, street smart, and criminally savvy characters in the film.
After accepting her final mission, Kate (Mary Elizabeth Winstead) is poisoned by an unknown assailant and must stalk her way through Osaka to find the culprit and serve them just comeuppance. Along the way, she interacts with a slew of primarily untrustworthy characters that impede her path to survival, many of which she must outsmart and over muscle before time runs out.
Stephen
While Stephen (Michiel Huisman) ends up proving to be a lowly sacrificial pawn used by much smarter and more powerful criminals, he was smart enough to read Kate's unimpressed body language when he approached her in a bar with his weak pick-up line. If courtship is an art that requires a modicum of social intelligence, then Stephen was wise enough to rebound from his early rejection, become much more honest with Kate, and succeed in his attempt to seduce her.
However, the smartest thing Stephen did was tell Kate about Sato (Koji Nishiyama), the ruthless criminal in the Kijima clan who she thinks is responsible for poisoning her.
Jojima
Japanese rockstar MIYAVI gives a ghoulishly entertaining performance as Jojima, a character whose smarts come in the form of advanced karate skills he uses to become Kate's most formidable hand-t0-hand opponent. He would have outwitted her in battle if it weren't for Ani bashing him in the head with a gun. As cool as he is, the assassin sort of sucks at his job.
But the wisest thing that Jojima did in the film, unlike many other characters, is refuse to rat out his boss. Jojima is smart enough to know that the consequences of naming his boss would be far worse than being bashed on the skull.
Renji
As Kijima's most trusted advisor, Renji's (Tadanobu Asano) intelligence derives from his ability to keep his dark duplicitous secrets from being discovered until the end of the movie. He presumably worked his way up the criminal empire using his cunning wits and wiles.
Renji manages to target Kate without Varrick (Woody Harrelson in an unmemorable role) or Kijima (Jun Kunimura) being aware of who is responsible, using his shrewd knowledge of the criminal underworld to operated undetected while appearing innocent on the surface. Once Kentaro was killed by Kate, all eyes were on Renji, who connivingly responded by slipping Kate the Polonium-204, It was a smart move at the moment but one that backfired in the end when he is confronted by Varrick and later by Kijima.
Varrick
As Kate's de facto father figure and mentor who trained her in the art of assassination, Varrick is a wise veteran of the contract-killing profession. In addition to teaching Kate everything she knows, the smartest thing Varrick does is conceal his identity as an antagonistic traitor working with Renji behind Kate's back.
Once Kate announces her last mission, Varrick fears that she will expose all of his secrets and teams with Renji to put a hit on her head. Alas, Kate has learned too much from Varrick in the ways of killing and dispatches him in a pretty uneven, anticlimatic showdown. While Varrick was smart enough to keep his secret identity hidden, he was no match for Kate in the end.
Kijima
With the utmost wisdom, experience, perspective, and compassion, Kijima was able to compartmentalize his grief over his brother's death and show sympathy for Kate's situation, which he is also smart enough to recognize parallels his own disloyalty.
As Osaka's most powerful crime boss and Ani's uncle, Kijima instinctively knows that Renji is behind the betrayal of the criminal clan, understanding that Kate has been set up as part of a large conspiracy. Despite being painted as the bad guy behind Kate's poisoning, the profound wisdom Kijima shows in knowing family is the most important thing leads to an unpredictable and redemptive twist for the character.
Ani
Although she is a foul-mouthed teenager, Ani demonstrates her street smarts on several occasions that help Kate on her mission. Firstly, Ani is the one who tells Kate about Renji and his swanky penthouse. Later, she uses her keen technological knowledge to hack into Renji's cellphone and track his GPS.
In addition to the crucial intel she provides Kate, Ani is smart enough to know when to physically protect herself and Kate, waiting for the right moment to strike Jojima in the head with a gun. Ani wisely saves Kate's life, which is repaid when Kate saves Ani from Varrick in the end.
Kate
It's no surprise that the smartest character in the film is the one the movie is named after. Indeed, Kate is a brutal killing machine whose intelligence reigns supreme in the art of being a professional assassin. She knows the ins and outs of long-range sniping, stealth positioning, escape planning, and has emotionally steeled herself for ice-cold dispassion.
That is until she shoots Ani's father Kentaro right in front of the little girl. As such, Kate's impending mortality comes with a dose of compassion and empathy when she wisely realizes she must protect Ani rather than use her as a pawn to lure Kijima out of hiding. Most of all, Kate is smart enough to know that she must complete her mission before she dies in order to deliver Ani from evil and give her a better chance in life than she had herself.