There were more people than expected. The line stretched all the way down the steps outside the auditorium. The stage lights were already on, and the black, white, and gray background perfectly complemented the soothing melody of the traditional zither.
Yu Xian sat behind the sign-in desk. Piled on the table were a stack of sample books, a standee with a check-in QR code, and a few paper bags containing souvenirs. His assigned task was simple: point at the QR code, nod, and say, "Thank you." Then, he would watch the attendee scan their phone. Once the words "Check-in Successful" popped up on the screen, he let them pass.
The Student Union staff guiding the crowd to the side had already shouted themselves hoarse. Gradually, the large auditorium filled up.
Absentmindedly pointing at the QR code, Yu Xian watched the phone screen in front of him show the checked-in status, but the person holding it didn’t move forward.
"Brother Cos?"
A crisp voice rang out from above. He was just about to remind this student that they could enter when the figure in front of the desk called out again, her tone carrying a hint of hesitation.
"Brother... Cos? Is that you?"
Yu Xian looked up and froze. Standing in front of him was actually the girl with the bun from yesterday. It was only then that he realized she was calling him—"Cos" was his screen name.
This nickname had a long history, dating all the way back to his third year of middle school. He remembered that during a math class, Xia Li had been giggling non-stop beside him. Her laughter left Yu Xian completely baffled. It wasn’t until class ended that Xia Li looked at him, her eyes curving into crescents.
"I discovered a secret! Animals aren’t allowed to turn into spirits after the founding of the nation, but trigonometric functions can! It turns out there’s a trigonometric function spirit right next to me. Guess who it is?"
The "trigonometric function spirit" naturally referred to Yu Xian, since his Chinese name literally meant "cosine" in trigonometry. Later on, whenever he was too lazy to come up with a screen name, he simply defaulted to the word "Cos." However, the pronunciation of this word was meant to be the mathematical "cosine," not the "cos" in "cosplay."
That was why he hadn’t reacted when the girl with the bun called him "Brother Cos."
"Uncertainty... Robot?"
After a moment of hesitation, not knowing how else to address her, he called out her screen name. He hadn’t expected her to be a student at JCU as well.
"Ah! You... you! How could you call me by my screen name in public!"
The girl’s face instantly turned red, and she stamped her foot in embarrassment and anger.
PFFT—
A suppressed giggle drifted over from the side. Only then did Yu Xian notice another girl standing next to her. Surprisingly, she also had her hair up in a bun. Their clothing styles, however, were completely different. One was wearing a loose, cartoon-patterned hoodie jacket, while the other wore a slightly classical dark teal coat.
The students waiting in line behind them were getting a bit restless. Seeing this, the two bun-haired girls grabbed each other’s sleeves and hurried inside.
"I couldn’t tell at all! This aloof, handsome guy is actually into cosplay? An anime nerd?"
"I didn’t expect it either. He looks so proper... You really can’t judge a book by its cover!"
As the two muttered to each other while walking away, Yu Xian’s hand, which was still pointing at the QR code, stiffened.
***
Inside, the auditorium was almost full.
The two girls squeezed into a row of folding chairs toward the middle-back. Their umbrella rested beside them, the hems of their pants still damp. Wen Xiao actually had no interest in this kind of chicken-soup-for-the-soul sharing session, but Shao Yiyi had insisted that the speaker was her academic uncle, so she had no choice but to accompany her.
"Confess. What’s your relationship with that handsome cosplay guy?" Shao Yiyi leaned in, lowering her voice with a face full of gossip.
Wen Xiao looked at her best friend helplessly. "What are you talking about? He’s just that guinea pig from yesterday."
Shao Yiyi looked as if she had discovered a new continent. She excitedly peeked toward the entrance.
"Whoa! So it’s him! Look, look, what did I tell you? How could our large model calculate it wrong? Hasn’t the husband of Sister Yuyu’s little sister arrived right on cue?"
"Shao Chacha! Keep spouting nonsense and see what happens!" Wen Xiao, blushing with embarrassment and annoyance, reached out to pinch her waist. The two girls tumbled into a playful scuffle in their seats.
***
With a sharp CLACK, the overhead lights in the large auditorium went out, and the audience slowly quieted down.
Yu Xian’s task was successfully completed. He was now standing in the staff area beside the main stage, watching the host walk up to deliver the opening remarks. From this angle, he had a clear view of the backstage curtain being lifted at the corner as an elderly man walked out from the side. The old man wore a gray cloth shirt. His hair was completely white, and though his pace was slow, his back was straight.
"Hello, students."
Su Mingyuan’s voice echoed through the lapel microphone. His speaking pace was unhurried—warm, gentle, and sincere—exactly the same as what Yu Xian had heard on the radio broadcast.
"It’s pouring outside, yet you were all still willing to come. Let me first say, thank you."
This opening remark clearly bridged the gap between the old man and the young crowd.
"Just now backstage, a student saw the words ’Doing Subtraction’ and assumed I was going to persuade everyone to embrace the ’lying flat’ lifestyle." He paused, a smile touching his lips. "Actually, that’s not the case. What I want to say is that effort is a scarce resource. Our generation has a huge problem: we are far too good at adding things. We always want to add tasks, add goals, and add expectations onto you young people. In the end, before your bodies even break down, your minds collapse first. My concept of Subtraction isn’t about telling you to stop trying; it’s about focusing your efforts on the places that truly matter."
After listening for a while longer, Yu Xian’s impression of the old man vastly improved. Previously, he had assumed Su Mingyuan was just a gimmick-driven expert—someone with "more style than substance."
But judging from today’s speech, he was indeed quite Boxue. Starting from social issues, he shared insights spanning the fields of psychology, philosophy, and economics, even dabbling in the natural sciences.
Yu Xian realized that the man was adjusting the density of his knowledge to convey his viewpoints across different settings. Although his core arguments were the same on the radio as they were here at the university, the supporting evidence he used was entirely different.