After apologizing to Si-woo, Seon-ah took Yurin to a spot where no one else could see them. "But you can't tell anyone," Seon-ah warned. "It's a secret. If you do, I won't do it again."
"Okay," Yurin agreed.
From that moment, a special secret formed between them. Afterward, Seon-ah continued offering kisses as a reward for correcting Yurin's "bad behavior." It was clear Seon-ah already knew Yurin didn't get along with the other kids. That initial specialness—being different from the others—transformed into something deeper. Seon-ah was different because he let Yurin kiss him, and he always said it was for Yurin's sake—actions that had nothing to do with Seon-ah himself but were purely for Yurin.
To Yurin, Seon-ah's words felt kinder and more helpful than her mother's weekend lectures. Thanks to Seon-ah's efforts, Yurin's strained relationships at daycare improved significantly. With kisses as an incentive, Yurin stopped her pranks. When a fight seemed imminent, Seon-ah would say, "Let's go kiss," and lead her away, leaving Yurin calm and docile by his side.
By the time they finished daycare before elementary school, Yurin could look back on those days with Seon-ah as fond memories.
Things didn't change much in elementary school. But after a certain incident, Seon-ah's reactions shifted slightly.
One weekend, during her mother's evening lectures—often fueled by alcohol—the topic of relationships between boys and girls came up. "You're about to start elementary school—what's with all this 'kiss' talk? Call it a kiss!" her mother exclaimed.
"There's nothing she can't say!" her father interjected, trying to stop her when the drunken scolding crossed a line. "It's too early to talk to a kid like that!"
Yurin wondered, "Does Seon-ah know the word 'kiss' too, not just 'peck'? I'll ask him to kiss me instead of peck tomorrow."
The next day, when Yurin asked Seon-ah for a kiss, his eyes widened in surprise. Those already big eyes grew even bigger, making him so cute Yurin wanted to bite him. "What's a kiss? What do you do for it?" Seon-ah asked.
Seon-ah was smart—always acing tests and solving Yurin's questions—but he didn't know what a kiss was? "A peck is another word for a kiss," Yurin explained. "I taught you, so want to try it?"
This time, Yurin was the teacher, and Seon-ah the learner—a reversal of their usual dynamic. Normally, Yurin would ask something, Seon-ah would answer, and then Seon-ah might request a peck. That was their way. It had been a while since Yurin last initiated a peck—or rather, a kiss. Being on the opposite side felt refreshing.
When they kissed, Seon-ah closed his eyes, unlike before. Afterward, his expression seemed off—almost like he'd expected something more. But when he returned to his usual self, Yurin figured it was her imagination. No, it had to be.
Seon-ah often got confessions from other girls, which he rejected bluntly, unlike a typical boy. "Sorry, I like someone else, so I can't." When Yurin heard those words, she was overjoyed—sure that the "someone" was her.
She believed their secret relationship would continue like this forever.
Occasionally, when Seon-ah visited Yurin's house, he'd try to get rid of anything in Yurin's room that felt "naughty." He'd even turn on the computer to check for risqué videos. Watching him, Yurin recalled something she'd heard: boys get jealous when girls use naughty magazines or items. Seon-ah's behavior seemed similar—perhaps he was anxious that Yurin might get hooked on such things and stop their "secret moments."
By high school, Seon-ah's baby fat had melted away, leaving him with a more mature, stunning face. Yurin, meanwhile, learned about sex from a college-aged cousin who gave her a risqué USB and books—things she barely understood in elementary school. Knowing Seon-ah's jealousy, she hid them carefully.
The acts in those treasures were leagues beyond movies or dramas. The books showed men and women in various positions, while the USB featured a man with a large member lying down as a woman rode him, sliding up and down. Watching it, Yurin felt her lower belly heat up, a tingling between her legs growing stronger with the couple's moans. Whenever the man groaned, she imagined Seon-ah's sweet voice overlapping it.
"If Seon-ah panted like that with his lovely voice…" She swallowed hard, her throat dry. Suddenly, a warm trickle flowed between her legs.
Later, her cousin explained that men usually get hard below, and women "swallow" it with their lower "mouth" to feel good—that's what sex was. Yurin wondered if she could try it with Seon-ah, who didn't even know what a kiss was back then. Seon-ah seemed to like naughty things—maybe he'd want to feel good together? But what if he looked at Yurin with disgust, refusing even a kiss?
After much thought, Yurin asked directly. "Yurin… sorry, but not that," Seon-ah replied. "How about we do it after we get into college?"
"No, I'm the one who's sorry. It was too sudden," Yurin said. Waiting until college wasn't a loss. More importantly, Seon-ah knew what sex was. The boy who didn't even know "kiss" in elementary school—had he kissed others? Was their "secret" just a lie while he did more with others?
Anxiety crept in. "Seon-ah, how do you know what sex is?"
"It's a secret. How could I say something so embarrassing?" Seon-ah rarely hid things from Yurin or called them secrets. Something was up.
"Really, you can't tell me? Between us? How can it be a secret?"
"Sorry. Is there something I can do instead?" Hearing that, Yurin—fond of naughty things—stopped pressing. Without proof, pushing further was pointless, and this was a chance to try something beyond pecks.
"Then let's kiss with tongues. That's a real kiss." They pressed their lips together as usual, but this time, Yurin slipped her tongue into Seon-ah's mouth, tasting his fragrance and softness. It wasn't as good as she'd hoped, and she started to pull away—until Seon-ah grabbed her face, sliding his tongue into Yurin's mouth. Wrapping around her tongue, teasing her gums, Seon-ah's movements left Yurin's mind blank.
Gasping for air, Yurin pulled back. Seon-ah looked at her, puzzled. "Why?"
"Sorry, I couldn't breathe," Yurin said.
Seon-ah laughed. "You can breathe through your nose."
Was this the Seon-ah who didn't know kisses? How was he so good at it? Something felt off. Realizing how skilled Seon-ah was with tongue kisses sparked unease in Yurin. Doubts grew, and the shadow of another girl behind Seon-ah began to claw at her heart.