Xie Kefu

Biodata

Feature	Details
Name	Xie Kefu (谢科夫)
Alias(es)	Andrei Sergeyevich Primakov
Species/Race	Human
Gender	Male
Affiliation	Jinghai University Mathematics Department; Lunar City Project; Song He's research team
Occupation/Role	Mathematician, programmer, researcher, and later biopharmaceutical postgraduate applicant
Status	Alive

Power Progression

Stage / Realm / Level	Chapter	Notes
Mathematics proficiency: +3 levels	214	Experienced a sudden enlightenment after Song He's explanation and received a return of mathematical knowledge.

Background / History

Xie Kefu is a Russian mathematician whose original name is Andrei Sergeyevich Primakov. He placed third in his undergraduate mathematics department and came to Jinghai University for a mathematics master's interview because passing it would allow him to enter the Lunar City Project's preliminary selection. Dean Cai gave him ten interview questions, all of which he solved. 211

He initially arrived with great confidence in his mathematical ability. Meeting Song He changed that outlook: after learning of Song's published mathematics work and broad achievements, Xie regarded him as a formidable rival. Encouraged by Katerina to represent their country's young mathematical talent, he began secretly studying at night to surpass Song. 213

Xie later entered the Lunar City Project's selection process alongside Song. He chose to travel to Ruoqiang Base with Song rather than pursue an opportunity at Tsinghua University, and scored 1,422 points in the written test. 276 272 During the project, he worked on the Space Window-Cleaning Bug program and eventually earned a Lunar City Project Silver Medal and a bonus exceeding two million. 219 726

Although he continued studying advanced mathematics, Xie gradually shifted toward applying mathematics to practical data-processing work. He later pursued materials-science mathematical analysis under An Yulong and began studying biopharmaceuticals in preparation for joining Song He's team. 696 726 727

Appearance

Xie Kefu is thin, with blond or yellow hair that is often described as messy and bird's-nest-like.

• Frequently wears bright red clothing, including red socks and underwear, believing it protects him from bad luck during his birth year. 214
• His yellow hair was compared by Fierce Zhang Fei to a Tibetan mastiff's fur. 267
• Can dress formally in a black suit, though his loose bearing undermines the intended scholarly appearance. 443
• His appearance and mannerisms become notably disheveled during prolonged mathematical work and drinking sessions. 236

Personality

Xie is proud of his mathematical background and highly competitive, especially when facing Song He. He repeatedly tries to compensate for the gap between them through longer study hours, late-night work, and relentless practice. His self-imposed rule for success is to work after his opponent has gone to sleep. 211 219

His rivalry with Song is tempered by genuine friendship and loyalty. He provides Song with textbooks, studies beside him, shares useful information, and supports Song's work even while feeling threatened by Song's rapid progress. 213 227 265

Repeated losses to Song make Xie more cautious and insecure. He can become despondent when unable to keep up with Katerina or solve difficult problems, at times drinking while working through mathematical dead ends. 236 1078 Despite this, he remains persistent, adaptable, and willing to change fields when mathematics alone no longer offers him a clear path forward. 727

Abilities & Skills

Mathematics

Xie is an accomplished mathematician with strong foundations, broad problem-solving experience, and a particular enthusiasm for tackling problems anywhere he can find them.

• Solved all ten questions in Jinghai University's mathematics master's interview. 211
• Ranked third in his undergraduate mathematics department. 211
• Provided Song with advanced Russian mathematics textbooks that Xie estimated would require one to two months of study. 213
• Gained three mathematics levels through sudden enlightenment after discussing a problem with Song. 214
• Participated in public Problem Duels, though Song eventually overwhelmed him with questions outside his knowledge base. 267
• Worked on the Sassoon Conjecture with Katerina and struggled with the pressure of matching her and Song's progress. 236 237

Programming and Applied Mathematics

Xie applies mathematics to engineering tasks, particularly the Space Window-Cleaning Bug program.

• Modified the program late into the night and improved its overall performance by 2.5%. 219
• Reached a ceiling while independently optimizing the program, motivating him to study difficult mathematics alongside Song. 227
• Later focused more on processing real-world data than advancing into unknown mathematical theory. 726

Biopharmaceutical Research

Xie deliberately retrained outside his original specialty to work more closely with Song's research efforts.

• Studied Song's brain-science and biopharmaceutical textbooks independently, producing extensive notes and completed practice papers. 727
• Applied to become Song's biopharmaceutical postgraduate student while working on the Lunar City Project. 727
• Served as a laboratory keeper responsible for mice and monkeys when not assigned higher-risk experiments. 1078

Flight Operation

• Earned a flying-car license and acted as Song's part-time driver during the New Year period. 1095

Relationships

• Song He — Began as a mathematical rival, but became Song's close friend, collaborator, employee, and prospective postgraduate student. Xie often measures himself against Song while continuing to support his work. 211 227 727
• Katerina — His fellow Russian mathematician and wife. Their relationship is affectionate but frequently strained by her intense mathematical work and Xie's insecurity about keeping pace with her. 213 237 1079 1528
• An Yulong — Mathematics mentor who formally accepted Xie as a disciple and guides him in mathematical analysis methods for materials science. 696
• Kong Gaojie — Mathematical opponent who challenged Xie and Song with six difficult questions shortly after their arrival at Jinling Institute of Technology. 268
• Fierce Zhang Fei — A physically imposing student who repeatedly bullied and teased Xie, calling him a “little Tibetan mastiff.” 267 272
• Valery — Xie's distant relative, an Academician whose rejected Chenghuang job application led Xie to alert Song about corruption in R&D recruitment. 697
• Lou Jinghui — Fellow researcher and conversational partner in discussions about difficult mathematical problems and the Dewitt Dinner. 789

Story Role / Major Arcs

Mathematical Rivalry with Song He

Xie's arrival at Jinghai University introduces him as a confident mathematics prodigy who expects to dominate locally. Song's extraordinary progress instead turns Xie into a determined rival, leading to secret late-night study, textbook exchanges, and public Problem Duels. 211 213 265 267

Lunar City Project

He accompanies Song to Ruoqiang Base for the Lunar City Project, joins the project selection and research environment, and contributes to the Space Window-Cleaning Bug program. His eventual Silver Medal demonstrates that he develops into a capable applied researcher even as Song continues to surpass him academically. 276 219 726

Sassoon Conjecture Collaboration

Xie tries to help Katerina prove the Sassoon Conjecture but becomes overwhelmed by the difficulty and her expectations. Song's unexpected progress creates an authorship dilemma, forcing Xie to reveal that the proof material he claimed to possess came from Song rather than himself. 236 237

Transition to Song's Research Team

Recognizing that his mathematical development has slowed, Xie studies biopharmaceuticals and applies to become Song's postgraduate student. He also becomes increasingly embedded in Song's laboratory and company-related work, including providing intelligence on Chenghuang's corrupt hiring practices. 727 696 697

Notable Quotes

“Others may not know, but I am very good at Mathematics!” 211

“The secret to success is to wait for your opponent to fall asleep, and you work one hour more than your opponent!” 219

“Actually... I don't think there's a need to compete so fiercely. Countries can sit down and have a friendly meal together.” 1079

Trivia

• Xie believes red clothing offers comprehensive protection against bad luck during his birth year. 214
• He once considered alcohol his response to mathematical fatigue, contrasting it with Song's habit of using oxygen inhalation while studying. 227
• A laboratory Big Mouse was named “Xie Kefu” after him; the mouse later set a life-extension record before dying. 762
• He is knowledgeable enough in Chinese history to recognize Lou Jinghui's allusion to the Chu–Han Contention. 1157