Jiyeon scratched her head with her right index finger, scrunching up her nose and forehead in confusion as she stared at Yoona. Why did she laugh? She didn't say anything funny. Didn't they go on a date last night? They definitely looked like a couple!

"Why are you laughing? What's funny?" Jiyeon asked with a tone of curiosity mixed into the interrogative feel. "And what do you mean by that? He and you seem like a perfect couple."

Yoona stopped laughing. "A perfect couple?" She puffed up her cheeks as if she were trying to hold back laughter.

"If you find something funny, don't hold back your laughter," Jiyeon told her, annoyance sharpening her tone. She hated it when she told someone the truth or she was being very serious about something, and they just laughed and took it as a joke. It fueled a lot of her frustration.

She took a deep breath, then cleared . "I'm sorry if I come off as annoying. Anyway he is my nephew, and you're not the first person who has mistaken him for my boyfriend," Yoona said, "isn't that funny, youngest teacher?" A goofy, lopsided smile lit her face.

They aren't a couple. He's her nephew? Jiyeon nodded her head up and down just a little.

She'd never had a relationship. Her parents had been extremely anti-boyfriend throughout her teenage years—and had always demanded that she'd waited until she'd finished her degree before she could date, especially her father. He had always stressed that she'd needed to focus more on academics and told her: "Boys will distract you from your studies." I've graduated from college now and have a good job, so why not start a relationship. Her face broke out into a huge smile, like a fresh bloom.

"You seem so happy, are you interested in him?" Yoona inquired, a teasing tone creeping into her voice, leaning toward her, which caused her to jerk backward.

She swallowed hard, blinking. "N-no, I'm not. I just remember something funny."

Yoona raised her brow, smirking. "You just remember something funny?" Disbelief colored her voice.

Jiyeon gave her a curt nod, then flinched a bit as the voice whispered in her ear, sounding extremely angry, "You're a liar. Don't try to approach him."

"Who are you? You don't have the right to prohibit me from doing what I want," she muttered under her breath. "I'll do what I want. It's my life, not yours. Get it?"

"I'm the voice of your heart—I have the right to do so," the voice rang in her ear, sounding soft yet firm. "I've told you he's a playboy. He and his aunt—they both are players."

Ignoring his voice, Jiyeon continued her way through the corridor. She could hear Yoona mumbling something before she followed suit. As they entered the class, all students stood up and greeted them in unison, "Good morning, teacher."

"Sit down," Jiyeon said, and the students sat down on their seats. "Okay, class. As you know, Mr. Song has retired and Ms. Im has joined us to take his place."

Jiyeon maintained the students' attention. She wished her students could be quiet like them and respectfully listened to what she taught. She then turned to Yoona and signaled to her to move to the center of the room at the front, where she introduced herself:

"Good morning, I am Im Yoona, and I will be taking you for Chemistry this year."

Jiyeon moved to the side and maintained her attention on Yoona, listening intently to her introduction. 

"I am pleased to have been asked to come and work at this school. I have taught in a number of other schools and am looking forward to working with you. Do you have any questions?"

Almost all students raised their hands, and Yoona pointed at a male student who sat right in front of the teacher's desk in the second row. The student smiled. "Teacher Im, how old are you? Are you single or married?" he asked enthusiastically.

"I'm 27 years old and engaged," Yoona replied, a small smile at the edge of her lips as she raised her left hand, showing off a yellow diamond ring on her ring finger. His smile faded, replaced by a frown of disappointment.

"Congratulations on your engagement, Teacher Im," all students said in chorus.

Yoona slightly bowed towards them and spoke softly, "Thank you."

Jiyeon tapped her shoulder. "Ms. Im, congrats on your engagement and good luck," she said. Yoona nodded, smiling.

"She's a playgirl—liar. She's not engaged," the voice echoed in her ear as Jiyeon went out of the class, heading to her class.

"Do you know her?" she mumbled under her breath.

"Of course I know her."

"What kind of relationship do you have with her?"

"She is my...she and her nephew have the same hobby namely toying with their couples' hearts. They are players, so you better stay away from them."

"She's your what? If you don't want to tell me, I'll find out myself."

"My girl, stay away from her, 'kay?" A note of pleading seeped into his voice. 

"Why do you—" Jiyeon blinked. Wait, I'm talking to the voice again? She didn't feel like being rational now. She felt like going insane. Quickening her pace, she shook her head. She entered the classroom, confronted with the chaos of noisy, uncaring students cracking jokes, throwing paper balls, and so on. She sighed in vexation.

"Good morning, class," Jiyeon greeted as she walked over to her desk.

They ignored her presence. She slammed her book down onto the desk, which caused her students to fall silent and look at her. However, a few seconds later, they started talking again. Anger flared hot on her cheeks. She clenched her fists, wondering why the students in this class didn't respect her! Was there something wrong with the way she taught?

Before she could open to shout, the voice whispered ever so softly, "My girl, don't be emotional. Just tell them that you won't teach until they are quiet and ready to learn. I'm sure they will quiet, though it may take a while to start working."

Closing her eyes, she took a few deep breaths in an effort to calm herself down. Then she did what the voice said. "I won't teach until you are quiet and ready to learn," Jiyeon told them in a flat tone.

To her surprise, her students immediately lapsed into silence—they sat neatly in rows, in their white uniforms with black ties, their hands folded in front of them. Jiyeon felt a warm feeling wash over her at the sight. Such good kids! Her smile vaporized.

"Page 40, exercise II A," Jiyeon announced and started to explain about volumes of solid of revolution; specifically, the ones with holes through them by the so-called 'washer method'. She used a piece of red chalk to draw a sketch of the curve.

She paused as she felt something hit the back of her head and looked down to see a paper ball on the floor. She turned to face her students, and the rest of the class pointed at the most recalcitrant student, who was busy tossing paper wads around the classroom. He seemed to enjoy doing so. He pumped his fist when it hit one of his classmates' head, grinning like an idiot.

"Lee Taeyong, come here!" she screamed at the top of her lungs, making the other students duck their heads down. She couldn't control her emotions anymore; she had lost her bike because of him.

"What's the matter, Yeonyeon?" Taeyong's voice took on a mocking tone—then stuck out his tongue at her.

"Come here, right now!"

"My girl, you should be more patience with him," the voice rang in her ear.

"Stupid, shut up!" she shouted in response to the voice. "Don't interfere with my business!"

Some of her students lifted their heads to stare at her, whilst other kept them down, and simultaneously they said:

"We did nothing."

"We didn't say anything."

Jiyeon blew out her breath in total exasperation. "I'm not talking to you guys."

"If so, you're nuts talking to yourself," Taeyong responded as he rose lazily to his feet. All students shifted their gazes to him. He had a slightly taunting smile on his lips as he walked over to her. Narrowing his dark-brown eyes, he looked her over from head to toe, slowly, then back up again, saying, "I have to admit you're beautiful and y, but unfortunately, you're crazy." He laughed, clapping his hands as if he'd told an extremely funny joke.

Two words that he emphasized and the sound of his laughter fueled her anger even more. Without saying anything, Jiyeon grabbed him by the arm, dragged him out of the room and into the corridor outside the classroom.

"Kneel down and raise your hands!" she braked, "stay here as long as I am in this class. You need not attend to my class!"

With a sharp glare, Taeyong did as he was told. Jiyeon's glare was as sharp as his, "This is punishment for not respecting your teacher," she hissed. When she stepped back into the classroom, her students were making noise senselessly.

"I think Jiyeon has mental issues. I've caught her talking to herself a few times," one of her students—who sat nearest the classroom door—whispered just loud enough for her to hear as she looked over her shoulder at her friend, who sat in the row behind her.

Her student's words made her burn inside. Jiyeon managed to stay calm and cool on the outside. Lowering her head just a little bit, her friend mouthed something to her, and she turned her head to look ahead of her. Her eyes flew wide with surprise.

"T-teacher Park—"

"Talking to yourself doesn't mean you're crazy or have mental issues," Jiyeon said, trying to sound calm. "According to the Quarterly Journal of Experimental Psychology, it has cognitive benefits."

The class lapsed into silence, but then one of her students with a shaved head, wearing round glasses—got up from his seat and started picking up paper balls from the floor.

He said, "Ms. Jiyeon, that kid just trash your room."

"That is nice of you to pick that up," Jiyeon responded as he threw them into the trash can located right next to the teacher's desk. A smile flashed across his face as he went back to his seat. She took a few deep breaths before she continued her lecture at the blackboard:

"With the washer method, it's easy to find the volume of something rotated around the x-axis, assuming it's defined in terms of x. If you have a function f(x), its area is—"

 As she wrote down the formula, her students started chatting again:  

"Let's go to the mall after school today."

"Okay, as long as you don't invite Sohyun."

"What have you got against Sohyun?"

"Don't yell. You must be lenient with them," the voice whispered in her ear as she squeezed the chalk in her hand.

Jiyeon stopped teaching and looked directly at the ones was carrying on a private conversation, waiting to establish eye contact, then said, "Would you please stop talking?"

She waited for them to answer; they lapsed into silence, biting their lips, and then she mouthed 'thank you'. The room was absolutely still while she continued her lecture, with students bending over their notes, writing.

Moments later, Jiyeon glanced down at her watch. "Do you have any questions?" she asked. To which receive no answer, she clapped her hands twice, adding, "Do exercise II A now."

The students nodded and began to do it. She walked around giving help where needed.

"Teacher Park," one of her students with her light brown bob haircut hanging just below her jawline—who sat three desks from the door on the left side of the room in the sixth row, just one row from the door on the left side of the room—called out, raising her right hand.

Jiyeon strode over to her. "Do you have any difficulties, Eunkyo?"

Eunkyo gave her a nod. "I'm confused by this problem," she answered, pointing at question number two.

Jiyeon bent over and used a red pen to draw a couple of sketches showing a typical cross section on Eunkyo's notebook, then explained, "In this case the radius is simply the distance from the x-axis to the curve and this is nothing more than the function value at that particular x as shown here." She pointed at the sketch that she had drawn. "The cross-sectional area is—" She wrote it down in the notebook—then continued, "Next we need to determine the limits of integration. Working from left to right the first cross section—"

"Ah, I get it!" Eunkyo tapped her right index finger on the desk, eyes glued to her notebook. "The first cross section will occur at x=1 and the last cross section will occur at x=4." She smiled at her.

Jiyeon nodded. "That's correct. Now integrate to find the volume."

A proud smile danced on her lips as she watched her student write down the formula. Nothing made her happier than seeing her students understand what she taught.

"The volume of this solid is 78π/5." Eunkyo looked at her, her eyes deepening with her smile.

Jiyeon tapped her shoulder gently. "Good job."

Soon enough the bell rang, signaling recess, was followed by general indecipherable loud chatter among the students.

"Thank you, teacher," Eunkyo said as Jiyeon stood up straight. 

Jiyeon gave her a quick, curt nod and moved in the front of the classroom. She clapped her hands, trying to get the students' attention, and the room suddenly became silent.

"Have you finished the exercise?" Jiyeon asked.

A couple of her students remained silent, while other replied simultaneously, "Not yet."

"Do it for homework. I'll check tomorrow." She went to her desk and grabbed her book.

The students groaned—frustration seemed to fill their voices. She stepped out of the classroom and stopped in front of Taeyong, who was still kneeling down on the floor while raising his hands over his head. He had his gaze fixated on the floor. Students walking by paused, stared and laughed as they walked past.

Jiyeon cleared . "Now follow me."

He rose slowly to his feet and narrowed his eyes at her in a glare. "Where?" Taeyong asked, "for what?"

"Office," she countered, trying to sound calm, "I'll call your parents."

"You've already punished me," he hissed, his hands balled into fists, "why do you have to call my parents? You're not yet satisfied?"

An audible sigh escaped her lips. "I'll tell your parents how badly you behaved," she answered as she leaned close to whisper in his ear, "if you think I didn't know you were the one who punctured my bike tire, you simply daydream."

He let out an irritated laugh before he spoke in a normal volume, letting irritation tinge his voice, "You need some kind of proof to accuse people of . Do you have—"

"No, but I'm sure you—"

"Don't accuse someone without evidence, youngest teacher," Taeyong interjected, a serious expression covering his face, then leaned close to her ear as he spoke in a low voice, "I like mocking you because I don't like you, but I'm not the kind that likes to damage to other people's property. You know I dislike you ever since you introduced yourself to the class in which you boasted about being the youngest teacher, and I promise I'll find the real culprit." He walked away.

The serious note in her student's voice shot a shiver down her spine. Jiyeon stood there like a statue, pondering. She admitted that she was always proud of herself for being a young teacher—she didn't think that her proud attitude could irk someone. For her own sake, she'd try to change it—she found it childish and immature. And she thanked him for letting her know the reason he disliked her. She did appreciate him being honest, but still his behavior was totally unacceptable. She was his teacher—he needed to treat her with respect.

"My girl, I'm proud of you. You've now realized that your attitude is childish," the voice rang soft and sweet in her ear, breaking her trance.

She clicked her tongue in annoyance at the voice's remark and walked as fast as she could towards the staff room. The rumble in her stomach reminded her she hadn't eaten yet. She entered the room and slightly bowed towards a couple of other teachers, who were discussing last night's football game and how unruly the students were.

Her stomach growled again as she placed her book on her desk. Mrs. Kim, who was sitting at her desk next to hers while reading a newspaper, let out a small laugh before she took out a red bento box out of her bag and opened it to reveal sandwich.

"Take this," Mrs. Kim said as she handed her the bento box.

Jiyeon shifted her gaze between the bento box and the old teacher. Mrs. Kim could hear her stomach growl? She thought only she could hear.

"Don't be shy. I know you're hungry," Mrs. Kim added, giving her a motherly smile.

A smile adorned Jiyeon's face. "This looks so yummy." She took a piece of sandwich. "Thank you, Mrs. Kim."

"You're welcome." She placed the bento box on the desk and continued reading.

Jiyeon sat down and took a bite of her sandwich. The savory cheese with a hint of spice twanged her taste buds. "Mmmm, that's good," she said and quietly devoured it. Then she looked at the bento box out of the corner of her eye. She wanted to take another piece, but she felt bad. She still felt hungry, so she excused herself and left the staff room. She briskly strolled towards the school canteen.

The canteen was noisy and packed. All the benches were occupied. As Jiyeon walked over to the counter, she heard a group of students, who were sitting at a table in the left corner of the canteen, talking about her habit of talking to herself. This truly made her insane. She shot them a stone-cold death stare, and they fell silent, lowering their heads. She bought a loaf of bread and a bottle of mineral water—then quickly left the canteen.

Jiyeon went to the school's rooftop and spotted Yoona sitting on the floor, leaning back against the fence as she looked up at the clear blue sky with a few passing clouds, talking to someone on the phone.

"Don't approach her. She and her nephew are players, so you better stay away from them!" the voice echoed loudly in her ears as she quietly walked over to her.

Rolling her eyes, Jiyeon sat down next to her. She put the bottle of mineral water beside her and unwrapped the small loaf of bread. Staring up at the clouds drifting high overhead, she began to eat.

"Youngest teacher, since when did you get here?" Yoona asked, a touch of surprise lacing her tone as she nudged her arm.

Glancing at her, Jiyeon replied, "A minute ago—" She opened the bottle and drank it. "Ms. Im, what's your nephew's name?" 

A teasing note slithered into her voice as she retorted, "You're really interested in him, aren't you?" Yoona gave her an infuriating wink, causing her to spit water out of .

Jiyeon wiped with the back of her hand before answering, "No, I'm just curious. He looks—"

"You don't need to lie to me. Your face is telling me the truth—it's red like a little strawberry. You look so cute." Yoona chuckled as she gave her cheek a playful pinch. "His name is Byun Baekhyun."

Jiyeon shoved her hand away. "Believe or not, I dreamed of meeting a young blonde man, who looked exactly like your nephew as well as his voice sounded precisely like Baekhyun's," she told her in the most serious tone she could muster.

A shocked expression crossed her features. "Do you mean this young man?" Yoona questioned as she showed her a picture on her cell phone.