Such things are certainly important to the authors themselves. I met with Guo last summer in a newly built upscale area on the outskirts of Shanghai, in the offices of Ke Ai (a homophone of the Chinese word for “cute”), the entertainment company he established in 2004 to produce teenage literary magazines like “I5land” and “Top Novel.” He enthusiastically demonstrated his encyclopedic knowledge of “American Idol” and his excitement at seeing the “Transformers”变形金刚 movie. An hour before the interview, I had phoned to ask if I could take his picture. He politely refused, saying an hour wasn’t long enough to prepare. “My fans worry about whether I look good, what clothes I wear,” he said. “There’s no way around it.”

　　All of Guo’s novels include a shy, mysterious hero who gets good grades and whose life otherwise parallels aspects of the author’s own. Guo was born in the southwestern city of Zigong, to an engineer father and a bank clerk mother who encouraged him to write. In 2001, when he was still in high school, Guo won first prize in a national essay contest sponsored by Mengya magazine. A short version of “City of Fantasy” — written, he told me, as relaxation therapy during his exams — was later published in the magazine and went on to sell more than 1.5 million copies in book form.

　　Guo’s second novel, “Never Flowers in Never Dreams,”梦里花落知多少 a love triangle featuring harmless forays into the Beijing underworld, was published while he was studying film at Shanghai University. It sold 600,000 copies in its first month. Soon after, Guo was accused of plagiarizing the novel from Zhuang Yu’s “In and Out of the Circle.” In 2006, a court ordered him to pay $25,000 to Zhuang Yu and to apologize. Guo paid the judgment but refused to apologize or admit any wrongdoing. The press was outraged, calling Guo “Super Plagiarism Boy,” a play on “Super Voice Girls,” the Chinese equivalent of “American Idol.” When the author Wang Shuo, famous for his best-selling novels about Beijing drifters and lowlifes published in the late 1980s and early ’90s, denounced Guo as an “out-and-out thief” with “no sense of decency,” Guo replied that it was only “normal for the previous generation to discipline the later generation.”

　　Guo remains unbothered by the episode. “A lot of people who criticize you, they haven’t read your works, they really don’t understand what this thing is, so I don’t pay attention to those opinions,” he told me.

　　Neither, apparently, do his fans. While the case was still in process, Guo produced a musical album, “Lost,” a thin spread of guitar and piano under lyrics about young love, performed by singers chosen in a national competition he organized. It sold 400,000 copies. Last year, his novel “Cry Me a River,” about the ostracism and suicide of a pregnant high school student, sold a million copies in 10 days.

　　Guo may have survived charges of plagiarism and bad writing, but today he faces what may be a more dangerous threat: even younger writers. The past few years have seen the rise of a group of teenage authors, sometimes called the “post-’90s” generation. Four years ago, 9-year-old Yang Yang received $150,000 for his novel “The Magic Violin,” about a young boy who is befriended by enchanted objects after his father disappears. It sold 100,000 copies. He has since published three more books and last year signed a contract for a 10-book series. Last month, Yang Daqing’s “Story of the Ming Expedition,” a novel about the Japanese invasion of Korea in 1592, supposedly written when the author was 13, hit bookstores. And 14-year-old Tang Chao’s second novel, “Give My Dream Back,” about unrequited love and suicide, was recently published with a first run of 50,000 copies.

　　Over the phone, Guo spoke dismissively of these potential rivals. “I don’t really know much about them,” he said. And they certainly don’t seem to be interfering with his plans. Guo’s next novel, “When We Were Young,” about four university students, arrives in stores in October. And next year, he plans to hold a national competition for young writers and to design his own line of stationery.