The next day, September sunlight filtered through the classroom's glass windows, casting a warm patch of light onto Jiang Shengyan's desk.
Up on the podium, the mathematics teacher was explaining the concept of sets. Jiang Shengyan lowered her head and quickly jotted down a few key points in her notebook.
Although she had already previewed this material during summer vacation, she still habitually marked the key points emphasized by the teacher.
She liked the feeling of reorganizing knowledge—much like wiping down every book on a bookshelf until it was clean, then rearranging them in her own way.
"Yanyan, do you know how to do this problem?" Her deskmate, Lin Mengke, leaned over, pointing to an exercise in the workbook. Her short hair swayed gently with the movement, the tips brushing against Jiang Shengyan's arm and sending a tickling sensation across her skin.
Jiang Shengyan glanced at the problem; it was about set operations. She picked up her pen and drew a Venn diagram on her scratch paper. "Look, the intersection of set A and set B is..."
Lin Mengke nodded in sudden enlightenment. "So that's how it is! I get it now, thanks, Yanyan."
Jiang Shengyan smiled faintly and pushed the scratch paper a bit closer to Lin Mengke.
After a full day of classes, the end-of-class bell rang, and the classroom instantly became lively. Jiang Shengyan packed up her schoolbag, planning to head to the bookstore to buy a few exercise books.
She could now easily finish the assignments given by the teacher, so she wanted to find some more challenging problems to work on in order to improve herself.
The bookstore was located directly opposite the back gate of the school. The moment she pushed open the glass door, the fresh scent of printer ink washed over her. Jiang Shengyan walked straight to the reference book section, her gaze sweeping quickly across the shelves.
"What kind of problems are you looking for? I can recommend some for you." A suddenly voice startled Jiang Shengyan slightly. She turned her head to see that Shen Jingyan had somehow appeared behind her. Even a standard school uniform looked exceptionally good on him compared to others.
"Why are you here?" Jiang Shengyan asked instinctively.
"Coming to a bookstore is obviously to buy books, surely not to eat dinner," Shen Jingyan said with a smile playing at the corners of his lips, teasing her.
Jiang Shengyan gave an awkward laugh, wishing she could find a crack in the ground to crawl into. What kind of brainless question had she just asked?
"Um... well, I want to find some slightly difficult math problems to work on."
Shen Jingyan stopped teasing her and glanced at the bookshelf.
"This one is pretty good."
He was holding a copy of *Advanced High School Mathematics Detailed Problem Explanations*, looking down and flipping through it.
Jiang Shengyan subconsciously took a step to the side, widening the distance between them. Shen Jingyan acted as if he hadn't noticed her movement, continuing to flip through the book in his hand. "If you want moderately difficult problems, this one is more suitable than that one." He pointed to the copy of *Must-Brush Gaokao Math Problems* in Jiang Shengyan's hand.
"Why?" Jiang Shengyan asked instinctively.
Shen Jingyan raised his head, a faint, ambiguous smile curving the corner of his mouth. "That one is too basic and lacks any challenge." As he spoke, he handed the book in his hand to Jiang Shengyan. "The problem design in this one is more interesting, and besides..." He paused. "The solution methods for some of the problems are quite special."
Jiang Shengyan took the book and flipped through a few pages. Indeed, the difficulty and line of thinking in these problems were very novel—exactly what she wanted.
"Have you bought these problems before?" She looked up at Shen Jingyan.
Shen Jingyan leaned against the bookshelf with both hands shoved into his pockets. "Pretty much. I've done a portion of the problems in here before."
"Thank you," she said softly. Was this what a genius student's vision looked like? She had to admire it.
Shen Jingyan straightened up. "You're welcome. If you run into any problems you don't know how to solve while doing these, you can ask me."
Thinking that a free private tutor was a bargain not to be missed, Jiang Shengyan smiled and nodded.
After saying that, Shen Jingyan exchanged pleasantries, checked out, and left. Jiang Shengyan noticed that the book he bought was meant for competition prep.
She put her newly bought exercise book into her schoolbag. When she walked out of the bookstore, the setting sun had already dyed half the sky red, and a light breeze swept past, carrying a hint of chill.
Returning home, Jiang Shengyan opened her exercise book and began working on the problems. These problems were indeed very challenging; it took her over an hour to finish just one small subsection, and she still had one problem left blank. She thought about it for a long time—her scratch paper filled completely—yet she still couldn't solve it.
Remembering Shen Jingyan's words that she could ask him if she got stuck, Jiang Shengyan hesitated for a moment before finally picking up her phone, taking a photo of the problem, and sending it to him.
"Are you busy? I don't really know how to do this problem."
"Let me take a look."
Jiang Shengyan replied, "Okay."
A few minutes later, Shen Jingyan sent an image containing his handwritten problem-solving steps. The handwriting was scribbled yet forceful, with every step written out in great detail. Looking at those formulas, Jiang Shengyan suddenly understood where she had been stuck.
"Thank you, I understand now," she replied.
"You're welcome."
On the other end, Shen Jingyan looked at the message pop up in the chat window and gave a light click of his tongue. "She's quite well-behaved this time."
He put away his phone and went downstairs for dinner.
When Shen Jingyan came down from upstairs, the dining room was already filled with the aroma of food. He lazily pulled out a chair and sat down, stretching his long legs out casually. Two buttons of his uniform shirt were undone, revealing a delicate expanse of collarbone.
"Why are you so late today?" Shen Linchuan asked casually, putting down the newspaper in his hand.
"Doing math problems," Shen Jingyan answered nonchalantly, his slender fingers already picking up the chopsticks.
Ms. Gu walked over carrying a plate of stir-fried vegetables, smiling warmly as she said, "Jingyan, Mom needs to discuss something with you."
"What is it?" Shen Jingyan asked.
"Your grandma called to say she doesn't want Tangyuan to come back just yet; she wants it to stay at the old residence for a couple more days. Your grandma loves it so much she hugs it all day and won't let go."
Shen Jingyan paused his chopsticks midway through picking up some food, pulling a deliberately aggrieved pout. "Mom, are you and Grandma trying to steal my dog?"
"You child," Ms. Gu gave him a reproachful look. "You're so busy with school now, when would you even have time to walk it? Besides, how happy Tangyuan is at the old residence—the courtyard is so big, it can run however it wants."
Shen Jingyan thought of their silly Samoyed, which always rushed forward to pounce on him in excitement every single time it saw him.
He gave a soft chuckle. "Fine, whatever. I really don't have time to take care of it right now anyway. But Mom, don't spoil it too rotten, or it won't recognize me as its master when it comes back."
"Of course not," Ms. Gu said with a smile. "Tangyuan is closest to you; every time it hears your voice, it perks up its ears and searches everywhere for it."
Shen Jingyan gave a lazy assent, though in his mind he was already plotting whether to visit that silly dog at the old residence over the weekend.
He hadn't seen it in a while, and he missed it a little.
After finishing his meal, Shen Jingyan stood up, ready to return to his room, when Ms. Gu suddenly called out to him, "Oh, right, Jingyan, your grandma said Tangyuan learned a new trick recently—it can do a backflip now."
Shen Jingyan's footsteps paused, the corners of his mouth curving upward involuntarily. "Really? Don't only cats do backflips? I'll have to go inspect the results this weekend, then."
Back in his room, Shen Jingyan opened his phone gallery and pulled up a photo of Tangyuan, which happened to be his profile picture.
The Samoyed on the screen was grinning wide, its round eyes seeming to brim with starlight. He gently poked the screen and laughed softly, "Silly dog."