Lin Yuyou

Biodata

Background

Lin Yuyou is Lin Yu’s younger sister. He remembers her as a well-behaved child who frequently clung to him, contrasting with her more mischievous behavior after starting school. Despite their frequent teasing and roughhousing, they remain close 45 46.

She attends a private high school and lives in a school dormitory. In her first year, she intervened when her timid classmate and roommate, Xu Ning, was being bossed around. The two subsequently became best friends 46 48.

Appearance

• Firefly notices that Yuyou resembles Lin Yu when she first meets her 38.
• Yuyou is popular with boys, though she dismisses their interest as being based on her looks 48.

Personality

Yuyou is outgoing, mischievous, and quick to tease. She mocks Lin Yu’s unconvincing sternness, pretends to be hurt by a light smack to win Firefly’s sympathy, and uses the threat of telling their mother to extract information from him. Her brother recognizes these tactics and often refuses to indulge them 39 45.

Beneath her teasing, she is protective of people she cares about. She initially assesses Firefly carefully because her brother’s happiness is at stake, then strongly objects when Firefly calls herself unworthy of him. Her supportiveness also extends to Xu Ning, whom she defends and encourages to become more confident 39 41 48.

She is proud of her academic performance but intensely frustrated by always finishing behind Xu Nian. She also dislikes evasive answers: both Firefly’s unexplained hesitation and Lin Yu’s instruction to “guess” leave her visibly exasperated 42 46 48.

Abilities & Skills

Academic Performance

• Consistently ranks second in her entire school year and has never placed first in an exam 45.
• Has finished only a few points behind Xu Nian in every school exam for three years 48.
• Plans to apply to Jiangcheng University, a choice her homeroom teacher questions because of her strong academic standing 48.

Acting and Persuasion

• Convincingly feigns pain after Lin Yu lightly smacks her head; Firefly believes the performance until Yuyou reveals the act 39.
• Uses affectionate pleading, teasing, and threats to involve others in her plans, though Lin Yu is familiar enough with her behavior to resist 39 45.
• Draws out Firefly’s feelings through questions about Lin Yu and a hypothetical confession 40 41.
• Her confidence can lead her to misjudge others: she initially mistakes Firefly’s nervous silence for aloofness and later underestimates her during a card game 38 45.

Clothing and Gift Advice

• Selects several outfits for Firefly during their shopping trip 43.
• Identifies drawing-related supplies as a suitable gift for Lin Yu, helping Firefly choose a present he appreciates 44 45 46.
• Advises Lin Yu that the thought behind a gift matters most when he later asks what girls like 50.

Story Role / Major Arcs

Mid-Autumn Visit

Yuyou visits Lin Yu at their mother’s instruction because her school holiday lasts only a little over a day, making a trip home inconvenient. She initially thinks she has the wrong address when Firefly answers the door, then is astonished to discover that her brother is living with her. Firefly invites her inside for lunch, and they become friendly before Lin Yu returns 38 39.

Yuyou questions both of them about their circumstances and begins assessing Firefly as a potential girlfriend for her brother. Neither reveals Firefly’s true origins to her 39.

Encouraging Firefly

During a shopping trip, Yuyou learns that Firefly would accept a confession from Lin Yu. At a café, she asks why Firefly has not pursued him and offers to help after hearing that Firefly doubts his feelings and considers herself inadequate 40 41.

Firefly declines without revealing the underlying reason—her unresolved Entropy Loss Syndrome and uncertain future. Unaware of this, Yuyou urges her not to keep suppressing her feelings 42.

Shopping Confrontation

At a clothing store, Wang Chengxu asks Yuyou to introduce him to Firefly. When Yuyou mocks him, he grabs her wrist and prepares to strike her. Firefly intervenes, stops his raised hand, and demands an apology 43.

Yuyou reassures Firefly afterward and is pleased to discover how protective she is. The pair continue shopping, and Yuyou helps her choose a drawing-related gift for Lin Yu 44.

Festival Celebration and Return to School

Yuyou celebrates the Mid-Autumn Festival with Lin Yu and Firefly over dinner, mooncakes, and cola. Later, she secretly watches Firefly deliver her gift and celebrates its success with her 44 45.

Before returning to school, she secures Lin Yu’s promise to grant her one wish if she enters a good university. On the journey back, she directly asks whether he likes Firefly. He avoids answering, but the question stays with him afterward 46.

University Choice and Continued Matchmaking

Back at school, Yuyou remains preoccupied with her brother’s love life. She also learns that Xu Nian intends to apply to Jiangcheng University, interpreting his choice as an attempt to continue their academic rivalry. Xu Nian instead defends her choice to their teacher and later thanks her for confirming her plans 48.

When Lin Yu messages her for gift advice, she immediately suspects that the recipient is Firefly and teases him despite his denials 50.

Relationships

• Lin Yu — Older brother. Their affectionate relationship includes teasing, mock arguments, and roughhousing. Yuyou actively tries to bring him and Firefly together 39 44 46.
• Firefly — Friend whom she calls “Sister Firefly” and hopes will become her sister-in-law. Firefly protects her during Wang Chengxu’s confrontation, and Lin Yu later encourages Firefly to treat Yuyou as her own younger sister 38 43 46.
• An Shuqing — Mother. Yuyou invokes her authority to pressure Lin Yu; her mother also arranges the festival visit and instructs him not to let Yuyou stay up late 30 39 45.
• Lin Chengting — Father 30 46.
• Xu Ning — Best friend, classmate, and dormitory roommate. Yuyou stood up for her when she was being bossed around and continues encouraging her confidence 48.
• Xu Nian — Academic rival who repeatedly takes first place ahead of her. Yuyou resents their narrow score gap and suspects his university choice is motivated by competition 48.
• Lu Xingfa — Homeroom teacher. He challenges her decision to apply to Jiangcheng University and scolds her when she stops listening 48.

Notable Quotes

“As long as you want to, I can help you!” 41

“Bro, do you like Sister Firefly?” 46