Chapter 26 – Domain of Definition

Transmigrating into the Heartthrob's Cannon Fodder Childhood Friend
102 Chapters

Chapter 1 - Transmigrating Into A Book Chapter 2 - School Transfer Chapter 3 - Linshui Chapter 4 - Xie Sui Chapter 5 - Giving Medicine Chapter 6 - Understanding Chapter 7 - Scuffle Chapter 8 - Home Chapter 9 - Living in School Chapter 10 - Xiao Xi Chapter 11 - Venting Anger Chapter 12 - Scared Of You Chapter 13 - Peppermint Flavored Hug Chapter 14 - Lagrange's Mean Value Theorem Chapter 15 - Bad-Tempered Father Song Chapter 16 - September Chapter 17 - Desk mate Chapter 18 - Wang Ci Chapter 19.1 - Zhu Zhixing Chapter 19.2 - Zhu Zhixing Chapter 19.3 - Zhu Zhixing Chapter 20 - Beating People Chapter 21.1 - Meeting Acquaintances Chapter 21.2 - Meeting Acquaintances Chapter 21.3 - Meeting Acquaintances Chapter 22.1 - Speech Chapter 22.2 - Speech Chapter 22.3 - Speech Chapter 23 - Traces of Living Chapter 24 - Your Husband, Brother Green Chapter 25 - Happy Together Chapter 26 - Domain of Definition Chapter 27 - My Deskmate Chapter 28 - husband Chapter 29 - PE Class Chapter 30 - Office Chapter 31 - You Reap What You Sow Chapter 32 - What kind of reward do I get? Chapter 33 - Hey Chapter 34.1 - Shushan Building Chapter 34.2 - Shushan Building Chapter 35.1 - It Hurts A Little Chapter 35.2 - It Hurts A Little Chapter 36.1 - A Slap In The Face Chapter 36.2 - A Slap In The Face Chapter 37.1 - Calling The Family Chapter 37.2 - Calling The Family Chapter 38 - System, Come Back Chapter 39 - Illness Chapter 40 - Shameful Chapter 41 - Lingering In Your Thoughts Chapter 42 - So Curious About My Grades? Chapter 43 - I’m Chasing You Chapter 44 - Monthly Examination Chapter 45 - Busy School Bully Chapter 46 - Results Chapter 47 - I’m Not Abstinent Chapter 48 - Deviation Chapter 49 - Qin Family Chapter 50 - Truth or Dare Chapter 51 - Ever Since I Met You Chapter 52 - Essay Chapter 53 - Banquet Chapter 54 - Equal Social Rank Chapter 55 - You’d Better Not Chapter 56 - Repair Chapter 57 - Internet Cafe Chapter 58.1 - Tastes Like Mint Chapter 58.2 - Tastes Like Mint Chapter 59.1 - Loving You Is Instinct Chapter 59.2 - Loving You Is Instinct Chapter 60.1 - Late Chapter 60.2 - Late Chapter 61.1 - Calm Down A Bit Chapter 61.2 - Calm Down A Bit Chapter 62 - Have You Calmed Down? Chapter 63.1 - Study Hard Chapter 63.2 - Study Hard Chapter 64 - Sports Event Chapter 65 - Childhood Friend Chapter 66 - Pretty Fierce Chapter 67 - Winter Camp Chapter 68 - The Last Life Chapter 69.1 - Crossing The Finish Line Chapter 69.2 - Crossing The Finish Line Chapter 70 - Unspoken Desire Chapter 71 - The Past Chapter 72.1 - 008 Chapter 72.2 - 008 Chapter 73 - Do You Believe In It? Chapter 74 - I Woke Up From A Dream Chapter 75 - Like Grass Before Spring Chapter 76 - ‘Nice’ Sidelines Type School Bully Chapter 77 - New Year Party Chapter 78 - Conversation Chapter 79 - Trapped Chapter 80 - Zhao Ziyu Chapter 81 - Waking Up Chapter 82 - Monday Night Chapter 83 - Who Will Go Back To A City Chapter 84 - I Don’t Like Them Chapter 85 - Open Your Eyes, It’s Dawn

translator: xiin
editor: butter

The first class of the first semester was mathematics.

Ma Xiaoding was more excited than anyone else, beating his desk at the back of the classroom, “Brother Yu, Brother Yu! Do you want to run for math class representative in a bit? I’m going to run for Chinese class representative? How about we go together, so that arts and science can bloom together.”

Song Yu was flipping through the compulsory senior high school textbooks. His eyes drooped lazily and he tsked when he heard his words, “You can bloom on your own.”

Xi Bowen was scared out of his wits and tried his best to persuade him, “That’s no good, Brother Ma, the Chinese class representative has to go up to recite books.”

Ma Xiaoding had no self-awareness and said complacently, “Of course I know. That’s exactly what I’m aiming for. I know so many poems, how could I not show them off.”

Xi Bowen said weakly, “Maybe you shouldn’t.”

The Student Bowen, who was passionate about learning, wanted to cry. He didn’t want to get a score of zero on ancient poetry in his college entrance examination.

When the ball rang, the math teacher came in with his teaching plan. He was about 50 years old, thin and balding, and wore glasses.

He held a thermos in hand, stepped up onto the platform, and slowly drank a sip of water.

“Students, I will be your math teacher this semester.”

He spoke each word slowly and emphasized each one clearly, making the listeners sleepy.

Ma Xiaoding whispered a complaint from the back, “Does every math teacher in the world have a face that makes people want to fall asleep when they look at it.”

Song Yu found him noisy, so he kicked out behind him, “Shut up.”

Ma Xiaoding silently made a zipping action over his mouth with his hand.

The first class generally didn’t cover any specific content. The math teacher slowly talked about his teaching plan and glanced at the students in Class One. “How about first choosing a class representative. Is there anyone who wants to volunteer?”

Ma Xiaoding was more excited than everyone else. He was quivering in his seat, his entire body wanting to act out as he suggested crazily, “Brother Yu, Brother Yu, Brother Yu! Brother Yu, go!” In his heart, Brother Yu was a strange person who worked on test papers during summer vacation and fought with trigonometric functions on the first day of school. How could he not have an official identity in their math class? Being the math class representative gave so much prestige.

More importantly, he wanted to run for the position of Chinese class representative! Arts and sciences blooming together sounded so damned cool!

Song Yu flipped his pen, wishing he could turn around and stab him with it.

Ma Xiaoding was too excited, to the point where his entire face was beaming with joy. His attitude was in sharp contrast to the drowsy and sleepy students.

The math teacher’s gaze landed on his face and his eyes brightened, “The student in the fourth desk in the third row from the back, it looks like you’re very excited. Since you’re so enthusiastic about math class, how about being the math class representative.”


Ma Xiaoding’s cheerful smile solidified on his face.

After ‘winning’ the position of math class representative, Ma Xiaoding finally calmed down. After that, he remained practically paralysed for the whole class, his expression seeming to say that there was no love in his life.

The corner of Song Yu’s lips curved briefly.

The bell rang to signal the end of class.

After math class, Ma Xiaoding ran out faster than anyone else. He quickly caught up to the math teacher, wishing he could fly all the way to the office to clear up this misunderstanding even if it cost him his life.

Song Yu was taking notes at the desk. A while ago, he’d done some test papers to find the feel for it. Now that he had the textbooks, he’d started to sort out his knowledge systematically.

Halfway through, he got stuck on a formula in a Wayne diagram. He poked the Xie Sui who was beside him with a pen, “Is this right?”

It was just that a girl’s voice sounded out at the same time as his.

“Student Xie Sui, may I ask what the domain of definition is?”

Her voice was sweet and soft, charming and moving.

The hand that was holding Song Yu’s pen paused. He looked up and saw a girl with a single ponytail standing in the aisle of the classroom with a pen and a math book. Her face was a little flushed, her eyes bright, and she was looking at Xie Sui. She was very attractive, and only girls who were particularly confident in themselves would be so proactive.

Xie Sui had been sleeping when he was woken up by Song Yu’s pen. When he first opened his eyes, the dark depths of his held a thin layer of deep chill.

When he saw the textbooks, desks, and classroom in front of him, the irritation and depression he felt retreated slightly.

The autumn breeze blew into the classroom, shifting the curtains. The youth’s eyelashes trembled and the emotion in those peach blossom eyes was very deep. He turned his head and looked at Song Yu, “What’s right?”


Song Yu was still holding his pen. He pointed silently at the girl standing beside them, who’d been completely ignored and now felt a little embarrassed, and said, “Why don’t you explain the domain of definition to her first?”

The girl forced out a laugh and repeated herself, “Student Xie Sui, I don’t quite understand the explanation in the book.”

Xie Sui shot Song Yu a silent look. He tilted his head, then smiling slightly at the girl, his attitude elegant and aloof, “Sorry, I don’t understand either.”

“Maybe you can try and memorize it.”

His tone was clearly light and casual, but there was always the feeling that he was insinuating that the other person was stupid.

The girl’s smile became increasingly stiff and the fingertips holding the pen turned a little white. She bowed her head and whispered, “Oh, oh. Okay.”

Song Yu watched the whole process.

He watched her trot back to her seat, then cover her face with a book in chagrin, then watched as she was comforted by a group of other girls.

He suddenly felt a little itch in his throat, and he wanted to say something.

For example, “You’ll lose a suitor this way.”

Another example, “You really don’t know what domain of definition is?”

One thing that Xie Sui didn’t lack the most during his previous life was suitors. He glanced lightly at Song Yu and said, “I know, but I don’t want to answer her.”

Song Yu: “…Oh.”

Xie Sui stretched out his hand and pulled over the mess of writing where he wrote whatever he thought of and came to some sort of conclusion, “What did you want to ask me just now?”

Song Yu was touched by his actions.

Brothers were like hands and feet, while women were like clothes!

“That’s the one!”

Xie Sui picked up the pen and wrote down the formula he was asking about. Then he casually changed a few things above it, instantly connecting many of the knowledge points together clearly.

Song Yu sighed emotionally when he retrieved his book, “Really worthy of God Xie.” However, he was still curious, “Why didn’t you answer? Speaking of which, even I know what domain of definition is. Why didn’t she ask me while she was at it?”

It was really a pity, the first time he had an opportunity to communicate with a female classmate from the same class in high school had passed by just like that.

Although Song Yu went against the heavens and the earth on the forums, his arrogant scum man temperament practically overflowing across the screen, in reality, Song Yu was still willing to help female students from the same class with their problems. Don’t ask, but if you do, he was simply willing to help others.

Xie Sui looked at his regretful expression. His eyes narrowed slightly, and his lips smiled slightly. His tone was very light, “Too basic. I usually only answer Lagrange questions.”

Song Yu: “……”

Damn it.

Was he never going to drop this matter.

Before the class bell rang again, Ma Xiaoding slunk back in like a ghost, holding a delicate strawberry cake in his hand.

Based on his broken and collapsed expression, it was clear that he wasn’t able to avoid being appointed the math class representative.

Xi Bowen couldn’t hide his joy, “Oh, Brother Ma, don’t be sad. Being the class representative for Chinese class and the class representative for math both mean that you’re a class representative. There’s no difference.”

Ma Xiaoding wanted to cry, “How could this be the same! Math class representative means that if my scores don’t pass, I’ll have to go to the office every day to do additional homework, just let me die!” However, before he ‘died’, he put the cake he was holding in his hand on Xie Sui’s table and said, “God Xie, a girl from the class next door asked me to give it to you. She’s quite pretty and is probably the class flower from Class Two. I think you can rest assured when eating it.”

Xie Sui looked down and glanced at the cake.

A post-it note was stuck on top of it, faintly scented and covered in a girl’s clean handwriting, ‘Hello, God Xie’ was written beside a smiley face.

Xi Bowen was genuinely stunned, “God Xie is really too popular.”

Song Yu tsked. Like he said, without a silly cannon fodder like Zhu Zhixing, Xie Sui’s high school life would definitely have been particularly lively. First in the grade and the school grass. In the school life era, he would definitely be popular throughout the whole school. 

However, Xie Sui didn’t even think about it before saying, “Thank you, but I don’t eat sweets.”

Ma Xiaoding’s eyes brightened, but he kept up the farce, “That’s too bad, but they’ve already given it to me, and I don’t feel good about bringing it back. How about I help you––”

Song Yu had already raised his hand, “Give it to me. I’ve never eaten a cake from a girl before.”

Ma Xiaoding cried pitifully, swallowing back the words that he wanted to follow up with. If Brother Yu wanted to fight for food with him, what else could he say?

Instead, it was Xie Sui’s smile that faded.

He tilted his head and said to Ma Xiaoding, “You have it.”

Ma Xiaoding: “???”

Song Yu: “!!!”

Song Yu: “What––”

Xie Sui opened up the compulsory mathematics textbook and pointed to the domain of definition with his slender fingers.

“Come on, I realized that I don’t really know what domain of definition is. How about you explain it to me.”

Song Yu immediately shut up. After being enthusiastic about learning for so many consecutive days, he finally had the opportunity to show off. He excitedly leaned over and said, “The domain of definition is actually very simple. I’ll find you a test problem, it’ll make things clearer.”

“……” Xi Bowen and Ma Xiaoding.

“Brother Yu is a little too easy to coax, right?”

Ma Xiaoding sat in the back eating the sweet strawberry cake with a spoon. His heart, which had suffered an injury due to math, finally received some comfort.

Xi Bowen pushed up his glasses, his eyes full of worship, “This is probably the difference between study gods and ordinary people. If there’s something that one test problem can’t fix, then use two test problems.”


Ma Xiaoding raised his fork in agreement.

He was more and more certain that Brother Yu really was a study god.

The last class in the morning was Ou Yilian’s class. Last time, she’d been so focused on giving her self-introduction that she’d even forgotten to do the introductions between students. So, this first English class of the semester became a class introduction.

Ou Yilian was still wearing high heels and a dress, and a cloud of perfume drifted around her.

“Last time, things were too rushed, and the students in our class didn’t get to properly introduce themselves. Well then, in this class, let’s get to know each other first.”

“We’ll start with the first desk at the front and go around in an S shape. Come, you go first. Come up onto the stage and introduce yourself. Tell us your name and hobbies.”

The first girl was still a little shy as she made her speech on the podium. She spoke very quickly and, after saying hello to everyone and reporting her name, she stepped down, her face red. Wang Ci hadn’t come to school today, so there was a row of empty seats where he and his young followers sat. This was very disrespectful to the class teacher, but Ou Yilian didn’t say a word. Her expression was very natural as she told the next person in line to continue.

Compared with the restrained girls, the boys were a little more cheerful. Even so, their words were very simple.

Ou Yilian frowned and wasn’t very satisfied with the effect of this round of introductions. “Why are you all so shy? You’re all stumbling and stuttering when you introduce yourselves. How about this, write your name, and don’t introduce yourselves anymore. Everyone can introduce their deskmates instead. You can’t be as shy when introducing someone else, right?”

Each person’s deskmate was their own choice. Most people already knew each other from junior high so, with this, the atmosphere became much more lively. When they came up on stage, there were all sorts of comments and witty remarks, teasing laughter and smiles from the audience.

According to the S-shape line, when it came to their group of desks, Ma Xiaoding and Xi Bowen were the first ones to go up and speak.

Ma Xiaoding was always the most excited one in the audience. He was supposedly introducing his deskmate, but after saying two sentences about Xi Bowen, he went on to talk endlessly about a variety of things. It was Xi Bowen who had to grit his teeth and drive him away impatiently.

When it came to Xi Bowen, this little pitiful bookworm, he stuttered for a long time, “My name is Xi Bowen, the ‘Bo’ that means profound, and ‘wen’ that means language. My deskmate… my deskmate…” When faced with the former junior high school bully as his deskmate, regarding his characteristics and impressions, he could only say, “He… he’s now the math class representative.”

Ma Xiaoding: “……” F*ck, he just had to go there.

When it was Xie Sui and Song Yu’s turn, the entire class fell quiet. After all, they were the two people whom the entire audience had been focused on since the start of school. Now, they still didn’t know their names. The girls all held their breath and focused, while some boys who were playing games also raised their heads.

Song Yu went up first.

Upon seeing him, Ou Yilian’s expression grew cold, and she started looking down at her cell phone.

He wrote his name down on the blackboard with chalk.

Song Yu turned around, then threw the chalk back into the box. His words and actions were simple and straightforward, “Song Yu, the ‘Yu’ that means metaphor.”

Ma Xiaoding started to cheer, clapping desperately, “Ohhhhhh, great, great, great!”

Amidst the silence and shock of the whole class, he was like a sand sculpture clown.

The whole class: “……”

Song Yu also looked at him like he was looking at a fool.

Probably because the tiny amount of shame he possessed reared its head, Ma Xiaoding once again chose to fall quiet.

The classroom returned to its quiet state.

Song Yu was born attractive, his skin pale and translucent, his hair and pupils a light brown. His entire person looked elegant and clan, but when he spoke, his words carried a willful momentum. When he stood on the podium, it was indescribably handsome.

Song Yu, the ‘Yu’ that means metaphor.

There was a round-faced girl at the front, her hair tied up with a star hairclip, her appearance very cute. When he spoke out his name, her eyes widened, and she was stunned for a long time.

Everyone was still in a daze.

In the quiet classroom, her voice was particularly noticeable.

“Is it… the same Yu as my husband Brother Yu?”

Butter’s Thoughts:
Brother Yu got exposed and met one of his wives today… in front of his green husband!

xiin: i love the way Xie Sui distracted Song Yu with… a math question. *facepalm*


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24 thoughts on “Chapter 26 – Domain of Definition”

  1. Is it bad that I totally want Brother Yu to be exposed? Hahaha! Give the fangirls something to eat!

    This teacher is still the worst. I look forward to some nice faceslapping action in the future!

    I’m not sure I’d consider Xie Sui as having game here. Math problems aren’t slick. It was a success though…?

    Thanks for your hard work translating!

  2. Hahaha YES! His identity is finally exposed! And he really is close with Xie Sui so the forums are going to completely explode with all this information? I can’t wait to see how this plays out.
    Thank you for the chapter!

  3. yeah, sy is confirmed shou. i mean, it was pretty obvious but i like the confirmation.

    ahahahahahah!!!!!! he’s so easy to coax. def shou material and cute to boot! no wonder xs likes teasing him so much!

    identity reveal, ahhhhhhh!

  4. XY seems to at least be in a one-sided relationship with the science subjects, maybe even studying in general. My condolences ? lets hope im not infected la~ i need to pass math to graduate

  5. The study slag in me kept inadvertently subconsciously replacing all the Domain of Definition with Domain Expansion(Ryōiki Tenkai) ¯\_( ಥ ‿ ಥ )_/¯

  6. I think I’m dumb, I was on the honor roll every year of high school but I can’t remember if I even learned about Lagrange or domain of definition?? Also wow, they’ve been in class together for a few days and English class is the first class they introduced themselves??


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