Si Di

Biodata

Feature	Information
Name	Si Di (司笛)
Alias(es)	Little Si Invincible; “4D”; Di Bao; Didi
Gender	Male
Affiliation	Well-Fed and Sturdy / Plump and Sturdy Entertainment Company; Limited Idol
Occupation/Role	Actor; Limited Idol trainee and group captain
First Appearance	Chapter 1
Age	21 7
Height	181 cm 7
Weight	63 kg 7
Education	Graduated from a 211 undergraduate university 7

Power Progression

Stage / Realm / Level	Chapter	Notes
Class F, Seat 101	6–7	Self-selects the gray F rank and the final seat, acknowledging that he has trained for only two days compared with the other contestants’ years of preparation.
Class F, initial evaluation	8–11	Remains F after performing “Baby, Baby,” but reveals exceptional flexibility, coordination, vocal potential, and rapid learning; Qin Wei casts the deciding vote to keep him in the competition.
Class F, theme-song reassessment	22–25	Challenges Class A ace Huo Xiao after three days of training. He loses and officially remains F, but Qin Wei replaces the F on his name tag with an honorary A, telling him, “In my heart, you’re an A.”
Popularity Rank 2	35	Rises to second place in the first public popularity ranking, directly below Huo Xiao.
Fox group captain	37	Chooses the challenging song “Fox,” recruits Ji Yan and three other suitable members, and appoints Yu Ning as the next captain.

Background / History

Si Di grew up across from Qin Wei, whose family has long been close to the Si family. Their childhood acquaintance developed into a bitter rivalry, intensified by Si Guohua repeatedly comparing Si Di unfavorably with Qin Wei. 1 3

An actor by profession, Si Di damaged his career after publicly calling Qin Wei a dog during his debut interview. The incident made him trend online but left him without meaningful work for a year and a half, while his manager Wu Biao personally funded their tiny agency. 1

Before joining Limited Idol, Si Di maintained an online relationship with “V” under the username Little Si Invincible. He concealed that he was an entertainer, presenting himself as a freelancer instead. 1 29

He joined Limited Idol as a last-minute replacement trainee after another contestant broke his leg. Initially, Si Di intended to underperform so he would be eliminated immediately and no longer have to work under producer and mentor Qin Wei. 4 5

Appearance

Si Di is a tall, slender young man with fair skin, a youthful appearance, and a strikingly expressive face. His appearance repeatedly attracts attention even from viewers initially hostile to him. 6 13

• Long eyelashes, which he calls his personal strength. 7
• Almond-shaped, bright eyes; his gaze is compared to that of a wolf pup when he is confrontational. 6 16
• Fair, smooth skin and soft, naturally textured hair. 13
• A slim waist and long legs. 23
• Able to shift dramatically between a lively, boyish image and a delicate, seductive stage image. 8 20 24
• Has a noticeable cowlick after intense performances. 25

Personality

Si Di is proud, impulsive, sharp-tongued, and fiercely unwilling to concede defeat—especially to Qin Wei. He responds aggressively to disrespect and public rumors, but distinguishes between hostility and kindness; he is courteous to people who approach him sincerely. 5 7

Behind his abrasive public reputation, Si Di is perceptive, self-aware, and compassionate. He openly recognizes the effort more experienced trainees have invested, helps lower-ranked contestants learn choreography, and refuses to define success as defeating weaker competitors. 7 18 19

He is also highly competitive. Even after losing to Huo Xiao, he accepts his shortcomings without surrendering his ambitions, promising to improve until he can challenge Huo Xiao again. 22 25

His emotional vulnerability is usually hidden beneath dramatics, insults, and bravado. This is particularly evident in his attachment to V and his distress when their online relationship collapses. 28 44 48

Abilities & Skills

Dance Aptitude

Si Di possesses exceptional flexibility, balance, coordination, and physical control, developed in part through yoga. 8 9

• Replicates hand and body waves after a single demonstration. 8
• Learns the complex Limited Idol theme-song choreography in one afternoon. 18
• Combines sharp timing with fluid movement and strong control in performance. 23
• Can break down difficult moves into simple steps for other trainees. 18 19

Vocal Ability

Although he has limited formal vocal training and struggles to read sheet music, Si Di has a clear tone, steady pitch, reliable rhythm, and strong high notes. 9 18

• Smoothly adapts when Zhao Yi unexpectedly raises a song’s key by half a step. 18
• Performs the demanding theme song while dancing after only three days of preparation. 23
• Handles the chorus, falsetto, and vocal runs of “Fox” with emotional control and a seductive vocal quality. 45
• Has no formal rap training and cannot yet perform difficult low rap sections reliably. 45

Rapid Learning and Memory

Si Di quickly absorbs new material despite entering the competition with only two days of preparation. 7 8

• Memorizes theme-song lyrics and choreography after limited practice. 18
• Improvises effectively when he forgets choreography during his initial evaluation. 9
• Improves rapidly through overnight training after recognizing the gap between his natural talent and experienced trainees’ discipline. 19 20

Acting and Stage Expression

Si Di is professionally trained as an actor, giving him a controlled voice and emotional expressiveness. 45

• Uses facial expression and vocal emotion to fit the seductive concept of “Fox.” 45
• Initially lacks stage experience, having only performed publicly twice by the time of his battle with Huo Xiao. 25
• Learns to treat stage presence as a skill that requires deliberate practice. 25

Teaching

Si Di is a patient and meticulous instructor when helping less experienced trainees. 18 19

• Corrects Yu Ning’s rhythm and arm movements through slowed demonstrations and counted beats. 18
• Teaches Class F trainees difficult choreography step by step until they understand it. 19
• Encourages trainees to rest and seek help rather than overwork themselves in isolation. 18 19

Equipment / Items

• Gray Class F uniform and rank sticker — His official initial and theme-song reassessment rank. 6 25
• Secondhand phone — Secretly given by Wu Biao so he can contact V; kept hidden from production staff. 26
• Down jacket — Lent to him by Huo Xiao. 43
• Warm clothes from Si Guohua — Blue-and-white striped long johns delivered through Qin Wei; Si Di refuses to wear them. 15 16

Relationships

• Qin Wei — Childhood neighbor and sworn rival; Limited Idol’s producer and idol initiator. Qin Wei votes to retain Si Di, recognizes his potential, and later becomes revealed as Si Di’s online lover V. Their relationship collapses amid concealed identities, jealousy, and misunderstanding. 1 10 25 43 48
• Wu Biao — Manager, agency partner, and frequent caretaker. Wu Biao scolds Si Di’s recklessness but continually supports his career, funds their company, trains him, and gives him a phone despite his disappointment over the Class F result. 1 4 19 26
• Yu Ning — Close friend and dormitory ally. Si Di protects him from Lu Chen, helps him train, and repeatedly encourages him to challenge himself; Yu Ning supports Si Di’s secret plans and teases him with increasing familiarity. 5 13 18 22 26 44
• Huo Xiao — Class A ace, rival, friend, and fellow Fox captain. Si Di chooses him as the strongest possible challenge, later confides that he already has an online boyfriend when recognizing Huo Xiao’s interest. 22 25 34 49
• Si Guohua — Father. A stern, authoritarian figure whose comparisons with Qin Wei fuel Si Di’s resentment, though he later shows concern by sending warm clothing and praising Si Di’s performance. 2 15
• Zheng Shu — Mother. More openly protective and affectionate toward Si Di than his father. 3
• Qian Er — Dance mentor and Si Di’s earliest professional supporter. He identifies Si Di’s natural dance talent and repeatedly defends his potential against Li Si’s objections. 8 9 24
• Zhao Yi — Vocal mentor. Recognizes Si Di’s pitch, rhythm, vocal range, and potential for rapid improvement. 9 18 45
• Li Si — Rap mentor and recurring critic. She insists Si Di’s current weaknesses should outweigh his potential and later publicly attacks his lack of rap training. 9 10 24 45
• Ji Yan — Third-ranked trainee and Si Di’s Fox teammate. He joins Si Di’s group to challenge his own ethereal image and defends Si Di when Li Si attacks his lack of rap experience. 37 45
• Lu Chen — Early dormitory antagonist. He judges Si Di based on online rumors, bullies Yu Ning, and is repeatedly humiliated or confronted by Si Di. 6 12 13

Story Role / Major Arcs

Career Stagnation and Rivalry with Qin Wei

Si Di’s feud with Qin Wei prevents him from securing roles and turns his public outbursts into online spectacle. Despite Wu Biao’s concern, Si Di refuses to apologize or abandon his pride. 1 4

*Limited Idol* Initial Evaluation

Recruited as a replacement contestant, Si Di enters intending to be eliminated. His intentionally simple “Baby, Baby” performance unexpectedly exposes natural dance ability, leading the mentors to debate whether potential merits keeping him. Qin Wei’s deciding vote makes Si Di choose to remain and seriously pursue the competition. 5 11

Theme-Song Training and Challenge

Si Di trains intensely for the theme-song evaluation, helps Yu Ning and Class F trainees, then recognizes that compassion must be balanced with personal discipline. He challenges Huo Xiao, loses, but accepts the result as motivation to improve. 15 25

Online Romance and Identity Crisis

Si Di attempts to maintain his relationship with V despite the show’s phone restrictions. He gradually suspects that V may be Qin Wei, while Qin Wei independently begins connecting Little Si Invincible to Si Di. Their concealed identities, accidental kiss, and jealousy over Huo Xiao lead to a painful breakup. 27 30 41 43 48

Popularity Rise and Group Battle

Si Di rises to second place in the first popularity ranking and becomes captain of a Fox group opposite Huo Xiao’s team. During rehearsal, he proves capable of carrying the song’s chorus but confronts his lack of rap training. His teammates, Ji Yan, and Huo Xiao support him against Li Si’s criticism. 35 37 44 49

Qin Wei–Huo Xiao Conflict

Qin Wei and Huo Xiao increasingly compete for Si Di’s attention, with both confronting him privately and treating his time as something to fight over. Si Di remains confused by their possessiveness and agrees to hear Qin Wei first, setting up Qin Wei’s attempt to clarify their situation. 38 40 49 50

Notable Quotes

“I want to stay.” 10

“If I don't understand, I'll learn. If I can't do it, I'll practice. Admitting defeat now doesn't mean I'll admit defeat forever.” 25

“Huo Xiao, I challenge you. One day, I will definitely defeat you!” 25

“Success isn't just about defeating the weak.” 19

“Are you two treating me like a tug-of-war rope?” 50

Trivia

• Si Di’s first stated strength on Limited Idol is that his eyelashes are “extra long.” 7
• His company’s name, Well-Fed and Sturdy / Plump and Sturdy Entertainment Company, embarrasses him during his introduction. 6 7
• He has a fast metabolism and is frequently shown eating bread rolls, meals, and snacks without concern for weight gain. 13 14
• Viewers give Qin Wei and Si Di the ship name Dichlorvos. 10
• Si Di considers himself an “iron-blooded tough guy,” despite repeatedly being perceived as cute, delicate, or seductive by viewers and fellow trainees. 14 20 24