He is eventually hired by a man named Macky Kam (Waise Lee) to ruin the romance between Che Man-Kit (Andy Lau) and Lucy Ching (Rosamund Kwan), who Kim is romantically interested in. Jing accepts the job and disguises himself as Kit's long lost brother, who takes very much after their eccentric father Yan (Ng Man-tat). Posing as Che's ditzy long-lost sibling, Jing goes on to ruin Kit and Lucy's relationship any chance he gets.
Tricky Brains, also known as The Ultimate Trickster, is directed by Wong Jing.
Tricky Brains provides examples of:
- Accidental Kiss: Under the influence of an aphrodisiac, Kit spasms as he tries to get his sexual desires under control. During this, he accidentally kisses Jing.
- Aerith and Bob: No one ever comments on the absurdity of the name Banana.
- And Now You Must Marry Me: A somewhat more positive version where Banana makes good on her promise to marry Jing in exchange for helping the Che family.
- Ash Face: Yan eats an explosive grape, leading to this.
- Bag of Holding: Jing's box of tricks that he uses against the Ultimate Trick Expert.
- Beneath the Mask: When Jing notices Banana upset in the bar because her boyfriend dumped her, he drops the stupidity act to try to cheer her up by messing with a bald guy.
- Berserk Button: Inverted. Yan becomes absolutely estatic and screams "Papa!" whenever someone mentions any words meaning "father."
- Completely played straight when Jing reveals to be faking as his son all along, causing Yan to not take any of his pity and his "Papa!" noises.
- Beta Couple: Jing and Banana get together at the end of the second act.
- Big Bad: Macky Kim
- Blatant Lies: Nobody is buying into the "fact" that Kit is a bad person, Macky. And Jing, don't pretend that you did not beat up executives and ruin a meeting on purpose just to get Kit in trouble.
- Bolt of Divine Retribution: Jing swears that if he lies again, he'll be struck down by thunder. Then it happens not two seconds later. Followed by repeated attempts when Jing swears yet again. Then it turns out the bolts of lightning were not aimed at him, but some guy outside the apartment.
- Character Development: Jing eventually comes to grow fond of the Che family. After he and Macky got both the father and son fired, he decides to betray Macky out of good conscience.
- Chekhov's Gun:
- The stomachache-inducing drink . He applies a stomachache-inducing substance onto Mr. Ching's drink, causing him to miss out on the meeting with the Japanese executives.
- The toilet contraption at Jing's office
- The "I <3 U" sign
- The irresistible aphrodisiac
- Chekhov's Skill: Kit was shown to possess good fighting skills during a Bar Brawl at a nightclub. He then uses these skills to take down the first group of Macky's guards (while dancing with his crossdressing father).
- Comedic Sociopathy: Being a movie about pranks, expect this a lot.
- Comically Missing the Point: When Lucy points out a "I <3 U" sign on a window, Kit reads it as "IOU".
- Cross Dresser: Yan disguises himself as Kit's date when they go to Macky's party.
- Crazy-Prepared: Jing has a plan to handle almost any situation, including a box full of random tricks that he uses at the end. When Banana comes to his office swinging a bat in anger, he dodges her every move and blocks her punches with metal sheets.
- Dance Battler: How Kit and Yan fight Macky's first batch of guards.
- Deadly Prank: Oh, does beating up executives of the other party in a meeting AND getting your "family" fired because of you counts as a prank, Jing?
- Dog Pile of Doom: The thugs at the nightclub Jing provoked do this to Kit and Yan.
- The Dragon: Jing to Macky, then replaced by the Ultimate Prank Expert.
- Drowning My Sorrows: Kit after his failed reconciliation with Lucy.
- Evil Counterpart: The Ultimate Trick Expert to Jing.
- The Fool: Even though Kit sees his "brother" as this, it's actually he who is the fool because no matter what trick Jing puts on him, he always manages to overcome it even though he doesn't realize what's happening.
- Forgot I Could Change the Rules: Averted when it comes to Jing's list of rules of the Trick Expert.
- Gay Moment: Jing and Kit accidentally kiss while the latter was under the influence of an aphrodisiac.
- Genre Savvy: Jing is well-versed in trickery enough to know that the gift basket Macky and the Ultimate Trick Expert left in his office is filled with explosive fruit.
- Hulking Out: Kit is forcefed some "irresistible aphrodisiac" and becomes extremely muscular and strong instead of overdosing and dying like intended.
- Impostor-Exposing Test: Kit and Yan, while joyed at finding a long-lost family member, realizes that they don't have any proof of their relation and decide to conduct an impromptu blood test. Luckily for Jing, his blood type is O-, which mixes with any blood type thus tricking Kit and Yan into believing he is for real.
- Inconvenient Itch: Jing applies itching powder onto Kit's clothes before they head for the cinema, causing Kit to itch around while waiting at the line there and trying to avoid being noticed by Lucy.
- Instant Costume Change: While pleading for forgiveness from the Che family, Jing somehow changes into a business suit while Yan briefly turned around. And then changed back to his pitying look, although Yan managed to catch him in the middle of his costume change.
- It Amused Me: Although Jing was told by Macky to make Kit's life a living hell, he does take opportunities to prank and make fun of other people like Banana, solely for this trope.
- Laxative Prank: In the opening, Jing tricks his victim into drinking tea that causes a stomachache, forcing him to use a toilet that is actually a prank contraption. He then applies a substance that causes stomachache (which could be the same stuff applied to that drink at the start) in Mr. Ching's drink, allowing Jing to ruin the meeting with the Japanese executives without Mr. Ching's presence.
- Leave Him to Me!: Jing confronts and faces off against the Ultimate Trick Expert while Yan and Kit go to confront Macky and his guards.
- Love Potion: Kit is fed an "irresistible aphrodisiac" by Jing in an attempt to ruin a date he and Lucy are on. Luckily, Kit managed to avoid making a fool of himself.
- Averted when Kit was forced overdose of said aphrodisiac. Instead, it temporarily makes him extremely muscular and strong, taking out a lot of Macky's guards as a result.
- Long-Lost Relative/Luke, You Are My Father: Jing invokes this trope to infiltrate Kit's family and get close to him. Then the ending reveals that Jing is indeed Kit's long-lost brother via a one night stand Yan had.
- Masochist's Meal: Jing pretends to eat tofu in the spiciest way possible. He then feeds said tofu to Yan, and then feeds him super spicy sauce to "calm" the spiciness.
- Mundane Made Awesome: Jing and the Che family discuss about how to apologize to Banana to the tune of Chinese opera.
- My God, What Have I Done?: Jing after getting both Kit and his father fired, which propelled his Heel–Face Turn.
- Naked People Are Funny: After getting a chief guard's hands stuck on his hair, Jing brings him out right in front of a large crowd and takes away his Modesty Towel, leaving him naked and panicking.
- Noodle Implements: Jing has all kinds of weird shit in his office, including a giant paper-maché head and a wine glass the size of a goldfish bowl.
- No OSHA Compliance: A door in Jing's office leads to outside with no balcony or whatsoever, as shown by the dude in the first act walking right into it and hanging on for dear life. Let's hope Jing does remember which door leads which...
- Obfuscating Insanity/Stupidity: Jing is a master at this. Count how many times he's not being stupid or insane while pretending to be Kit's sibling.
- Overly Long Name: Jing prefers to be called the "Handsome Trick Expert" (it's much longer in Cantonese).
- Pants-Pulling Prank: Jing swiftly does this to the Ultimate Trick Expert in retaliation to the shock device planted in the latter's hand.
- Pet the Dog: Jing buys 128 roses for Banana on her birthday, even before she got broken up with by Julian.
- The last act of the movie is Jing trying to fix the damage he did to the Chi family.
- The Prankster: Koo Jing, the Trick... er-hem, the Handsome Trick Expert. So is the Ultimate Trick Expert, and Jing is not pleased when that guy comes to usurp his title.
- Punch-Clock Villain: Jing. People pay him to trick some person or make that person's life hell. Let it by good people like the divorced woman at the beginning, or evil-intentioned folks like Macky, Jing will do it on whoever they want him to pull pranks on. Subverted in that Jing seems to enjoy what he does, since he goes out of his way to fool Banana.
- Punched Across the Room: Jing delivers one to the Ultimate Trick Expert with his mechanical boxing glove.
- Relocating the Explosion: Jing relocates the gift basket trap into his toilet contraption, which blows up the toilet.
- Rule of Funny: It has Stephen Chow in it, so expect plenty of mo lei tau here!
- Sanity Slippage: Appears to be the worst thing to happen if Jing is ever hired to trick you, as exemplified by his first on-screen victim.
- Sparse List of Rules: Jing's rules of being the Trick Expert. We don't get to hear a lot about it, but all we know that he set those rules up, cannot change them at all, and most importantly, has to go celibate should he break any of them. And they sound ridiculous, too.
- Spear Counterpart: Banana to Jing; apparently she gets paid to fool men sexually.
- Spontaneous Choreography: Played for Laughs with Jing and Kit's horrendous singing about working hard... which ends in the two falling down the stairs.
- Stab the Salad: After getting fired Kit and Yan fired, Jing prepares to defend himself in case of retribution coming from them due him thinking to his identity was broken as a result of causing the two to get fired. Kit and Yan walk up to his bedroom, sinisterly holding a knife... and surprise! It's Jing's birthday!
- Sticky Situation: First to a chief guard when trying to wash away the dust from Jing's ring box trap by Jing swapping out shampoo with super glue, causing his hands to be stuck on his head, then Jing splattering super glue underneath the muscle-stiffened, retreating Ultimate Trick Expert's feet.
- Strong Family Resemblance: Jing's mother is basically a gender-bent version of his. Both are played by Stephen Chow.
- The Trickster: Jing is a master of this trope, as well as his eventual nemesis, the Ultimate Trick Expert.note
- This Banana is Armed: Not a weapon, but literally as a shock device, which Jing uses against the Ultimate Trick Expert.
- Trouser Space: Played for laughs as Jing pulls out his briefs from his pants, and Kit does the same too but accidentally rips his own briefs instead, shown as they both put it on over their pants, revealing that Jing hid spare pairs of briefs inside his pants.
- Truth Serums: The Ultimate Trick Expert shoves a bun full of "Honest Paste" into Jing's mouth to make him tell the truth for thirty seconds. However, Jing manages to switch the bun out with one filled with "Lying Paste". He then gives the Expert a lolipop that causes him to ashamedly reveal his past crimes. Also that he's gay.
- Wedding Deadline: Subverted in that while the circumstances and measures taken are what one would expect, the main characters are actually trying to stop Macky from proposing to Lucy.
- "Which Restroom?" Dilemma: Played for laughs as one of the employees tricks Jing into entering the ladies' restroom (even though anybody with the simplest understanding of English can tell which restroom is for which there), and then Jing tricks Banana into entering the gents' restroom by playing dumb. Said same employee asks Jing to enter the ladies' restroom again to get a piece of tissue paper there, and Jing manages to scare the living daylights out of a secretary there.
- Villain Protagonist: In a weird way, Jing. Fortunately he turns against Macky later on.
- What the Hell, Hero?: Banana calls out Jing for ruining the Che family after he got both of them fired.
- Wrong Genre Savvy: Macky thinks that a lion dance troupe heading for his party are Jing, Kit and Yan and asks his guards to beat up said lion dance troupe, only to reveal that the performers are actually Mr Ching and his old pals.
- You Have Outlived Your Usefulness: After Jing refuses Macky's request of throwing one more "prank" at Kit after getting both Kit and Yan fired, Macky hires the Ultimate Trick Expert to ensure that Jing will not interfere in Macky's proposal to Lucy.
