Kin Cheung / AP A student passes by teacher posters as she leaves after a tutoring class in Hong Kong on Dec. 4, 2013

Kelly Mok first saw Hong Kong’s celebrity tutors blown-up on billboards above the highway and plastered alongside buses. “Are they tutors?” she wondered. They looked more like South Korean pop stars, with their hair cut at a half-dozen lengths and brushed in a half-dozen directions. But the ads clearly labeled them as tutors, albeit “tutor kings” and “queens,” and she wanted to be one.

A few years and several thousand students later, Mok, 27, worked her way up to the title of “tutor queen” at King’s Glory Education Centre. Now it was her face plastered on the sides of buses. “Dad, look,” she said as one whizzed past the passenger-side window of her car. “That’s me!”

To thrive in Hong Kong’s exam-based school system, students must master the art of cramming. The city thus has an overwhelming demand for tutors who can do an end run around the curriculum. Some 85% of Hong Kong’s senior secondary-school students seek out some form of private tutoring, a $255 million industry, according to the Asian Development Bank. “We need some strategies,” explains Martin Hui, a 17-year-old student at King’s Glory, “some tactics that we can use in this war,” emphasizing the last word with a pound of his fist on his notepad.

The top tacticians can draw as many as 10,000 students a month. With this army of pupils paying $65 a course, the most popular tutors can command salaries upwards of $3 million a year. Some luck-of the-draw students will see their tutor live, in person. The vast majority will watch the tutor on tape via closed-circuit television. An administrator at King’s Glory hits play, and the show begins. Naturally, the telegenic tutors thrive under these conditions. “Idol worshiping is an irresistible trend in modern society,” says Shum Yi-fai, the wizard behind Mok’s fame. “I make use of this.”

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Shum, a formidable tactician in his own right, built King’s Glory from a single tutoring center to a sprawling franchise of 29 centers across Hong Kong. Students from grades 1 through 12 file into his classrooms every day after school. King’s Glory claims that they stand to improve their test scores by two letter grades on average. Shum boils his success down to one simple revelation. As a former private tutor, he traveled from house to house, and he noticed that everywhere he went, parents and students made a singular demand: “No knowledge, only results.”

With an eye toward results, Shum streamlined the curriculum. “Don’t teach rubbish,” he says, rubbish being any knowledge that won’t appear on an exam. He divided the coursework into “injections,” as he calls the daily lessons. Then he recruited tutors who could administer the injections as quickly and painlessly as possible. Few things could ease a teenager’s troubled mind quite like a pretty face. “I categorize some teachers to be beautiful girls, handsome boys,” Shum says. “Kelly is very beautiful. Have you seen Kelly Mok?”

Most of her students had seen her in an advertisement before they saw her in the flesh. She looks “appealing,” Aaron Cheng, 17, says with a shy grin, as his appealing tutor stands several feet behind him in a knee-high skirt. “I’m a boy so I can say that.” The girls can say it too. “She’s attractive,” says Candy Wong, 18. “That’s one reason I can pay attention.”

But looks are just the lure. The hook is a lesson stuffed with tricks they’d never learn in day school, like a time-buying phrase for the English oral exam. “If they pause for too long,” says Mok, “the examiner will think, ‘Are you lacking vocabulary or you don’t understand the question or what?’ So we’re going to teach them phrases that will help them to start talking immediately.”

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Mok gives an example of a prefabricated phrase. “Well, that’s quite a controversial issue at the moment,” it begins and continues for a paragraph. The student can rattle it off while formulating a more direct response to the examiner’s question. Plus the student unleashes that big, point-boosting word — controversial — right out of the gate.

But what really reels in a student night after night is not the looks, not the lesson plans, but the tutor’s charisma, that star quality that every tutor at King’s Glory wants, even if they don’t quite know what it is. Shum alternately describes it as “speaking skills,” “showbiz gestures” and “instinct.” Mok simply says: “It’s hard to explain.”

Whatever it is, everyone agrees that tutor Alan Chan has it. “When he stands in front of the class,” says Mok, “he’ll say something that the students will remember immediately — like, for life.”

During one class, Chan, 34, wears a twinkling gold bow tie and a gray sweater cinched at the arms. His performance, and there is no other word for it, is freakishly commanding. He gestures like a talk-show host. He locks eyes with the students, as if he were personally confiding in them the essential tip of the day. Then a broad smile wrinkles his face, spreading a contagion of smiles throughout the classroom.

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This gift for gab comes with practice. Chan spent the first few years on the job reviewing videos of himself in front of the classroom. He squeezed training into every free moment of his 12-hour workday. During his commute, he listens to the latest K-pop hits, which help him relate to his students. He jogs to strengthen his lung capacity for 12-hour speaking marathons (Frank Sinatra adopted the same tactic to carry a song). He flips through fashion magazines, absorbing the cutting-edge styles of South Korean pop stars, and then books a flight to Seoul to buy the same clothing off the rack. And his hair, a textured, multidirectional marvel, takes 15 minutes to style every morning with a comb, spritzes of hair spray and a thin coat of a popular sculpting cream called clay. He might be the hardest worker in the tutoring business. “Because I want to be the best tutor,” he says.

Chan’s students repay him with attention verging on adoration. One girl comes up to his desk after class to give him frosted cupcakes for his birthday. When they are lined in a row, they spell out A-L-A-N in chocolate chips. Another has given him a collage of his pictures cut out from brochures and pasted to a poster board with the words Precious Memories written in cursive at the top and underlined with squiggles.

Getting this undivided attention is perhaps the greatest feat of Hong Kong’s celebrity tutors, because the students come to King’s Glory exhausted. They spend the day cramming at school and study until midnight or later. Every student interviewed said they dropped extracurricular activities in preparation for the mother of all tests, the college entrance exams. One abandoned his position as captain of the basketball team. “I would go home and dream about basketball,” he says. Another quit trombone. A third shelved Chinese calligraphy, swimming, badminton and bowling, all for the exam. And one, Joan Yeung, 17, stopped thinking creatively about poetry, a course that she loved, so that she could train her thoughts on the exam’s interpretation of poetry. “I hate that kind of model answer,” she says. “You can’t explore your own feelings.” Perhaps not, but for Hong Kong students like Yeung, that’s the price of killing an exam.

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