It's gonna be January 10th next Sunday, Bona realises, and she releases a sigh. She doesn't know what to do for it.

The week passes. Bona hasn't been giving it much thought.

"Unnie!" Yeoreum screams across the otherwise peaceful home.

"Hmm?" Bona hums an unbothered reply without taking her eyes off her homework before her.

Yeoreum stands from the floor and watches the focused Bona being so concentrated in her schoolwork that it fascinates the former.

"What's up Yeoreum ah," Bona finally looks up due to the lack of response.

Yeoreum's eyes turn into crescents as she smiles, "Nothing unnie."

Bona's lips purse together and curve into a small smile. Bona doesn't turn back to the lines on the book although her pencil is still tightly within the grasp of her right hand; her eyes remain on her sister when in times like this she realises how adorable Yeoreum is.

"You know, I went back to school the other day," Sojung walks over to join Bona at the coffee table where the latter is frantically trying to salvage her data from her almost-dying laptop into an old hard drive.

"You didn't tell me to?" Bona lifts up an eyebrow.

"It was Wednesday! You had your late- what was that, Bayesian?- whatever it was, lecture," Sojung says as she settles herself down beside Bona.

"How are things back there?" Bona asks, ignoring Sojung's blabbering.

"You know, Joo ssaem left! I can't believe he left," Sojung says, rather animatedly, much in contrast to Bona who is only moving her fingers on the mousepad of her still slightly cooperative laptop.

"Joo ssaem? The language teacher?" Bona replies with another question.

"Yeah! And oh, remember Park ssaem? She taught us Math. She knows you pretty well, does she?" Sojung continues recounting her visit to their alma mater, "She asked if a certain Yeoreum is your sister."

Bona's hasty fingers freeze at the instant. "She asked about Yeoreum?"

"She said there was too much resemblance between the two of you, and that Yeoreum takes after you so much she felt like she was teaching you again. Except that big difference where Yeoreum hates math but math is your life," Sojung explains to the mildly surprised Bona. 

Bona doesn't know why she's stunned to this extent, but she is. "Yeoreum is that similar to me?"

"Haven't we established that? You used to talk about her all the time that she's exactly you in a younger body. How the two of you would make the same replies to your parents, have the same preferences, and cry over the same things-" Sojung stops when she sees a hardened expression on Bona's face. 

"Yes," Bona softly whispers, her voice heavily tinted with guilt."I'm having a bad feeling about this."

"I just realised you haven't talked about her since..." Sojung pauses to think, "since our last year in high school."

"Right, I haven't," Bona's heart sinks as she admits it.

The both of them know why she feels bad.

"Didn't she used to call?" Sojung's voice cracks when she speaks after a gulp. 

"Ah," Bona rolls her eyes to think, "when she was still in her last year of middle school." Perhaps life absorbed her sister in when she became a high schooler just as how it was for Bona as a college student, and perhaps maintaining anything without being able to see each other was difficult anyway. Bona admits that she has much of an "out of sight, out of mind" mindset as well, and she remembers not being the most receptive person to their calls. 

The loud thunder shakes Bona, but the middle-schooler can admit that she's rather calm despite the roaring in the dark night, as compared to when she was younger, perhaps when she was an elementary schooler.

"Unnie, can I sleep with you?" Bona is startled by a sudden whisper by her ear, an added scare to the horrifying night.

"Yeoreum! You scared me," she narrows her eyes at the little one. "And you know my bed is too small."

But the thunder roars again and Bona understands immediately why. Despite shaking her head, Bona sits up and shifts to make way on her bed, enough for another occupant.

"Gomawo unnie," the young one mumbles as she climbs in beneath the sheets, partly excited, partly relieved, but also with visible guilt. Bona wonders how one can express so different emotions at once, and inwardly laughs at her as her heart swells watching Yeoreum's adorable behaviour.

"Is unnie scared?" Yeoreum asks within Bona's arms.

"No, and when Yeoreummie grows up, Yeoreummie won't be so scared too," Bona speaks with reassurance in her voice.

"But can I still ask unnie to protect me?" Yeoreum poses an unexpected question in response.

"Unnie will always be protecting you," Bona smiles, even if you don't ask me to, she silently completes the sentence.

"Is this a promise?" Yeoreum sticks out her right pinky.

Bona lightly laughs, "It's a promise," and seals the pinky promise. "Just remember unnie's always in your heart, even if I'm not beside you," she adds with a smile.

"Am I in unnie's heart too?" Yeoreum asks in reply.

"Definitely."

Bona opens the last folder titled "356137841" (she doesn't know what the numbers mean) in the old hard drive after everything is transferred from the laptop that she now considers as junk metal. She finds photos of her home that she hasn't returned to in a while, and as she scrolls to the bottom, an old photo taken of her and Yeoreum when they were children. Yeoreum had herself in a blue dress, while Bona was in one exactly the same but in pink instead. Their hands were held tightly. Bona stood a head taller than Yeoreum.

The image is titled "20040110_1362", Bona notices when her eyes happen to land where the numbers were. This time, she knows what the numbers mean.

"Unnie, did you like middle school?" Yeoreum asks on the Friday night of her first week as a middle schooler.

"It's more fun in high school," Bona smiles, "why?"

"So I should wait three more years for the fun?" Yeoreum seems a little disappointed with the reply Bona has given.

"Do you not like middle school?" Bona tries at understanding the point of Yeoreum's questions.

After three seconds of stillness, Yeoreum shakes her head.

"Why?" Bona frowns. She suddenly notices how red Yeoreum's eyes are. 

"Some girls in my class don't like me," Yeoreum timidly answers.

Bona furrows her eyebrows. "Really?" 

"They're scary," Yeoreum says.

"Don't worry, unnie will protect you," Bona answers with conviction. Anger slowly builds up within her at the thought of anyone having made her sister cry.

"Really?" Yeoreum lifts her head up and their eyes are aligned.

"Really. I promise," Bona replies with her eyes looking into Yeoreum's.

And for how long has she forgotten that promise? How is Yeoreum doing in high school? Being in high school has its share of scary or stressful happenings too, Bona can safely say, but who is protecting Yeoreum? 

Who is listening to Yeoreum when she needs to speak, because the kid probably doesn't even open much to anyone else- because who else would listen to her? Who will be with her when she cries?

Bona has cried alone, and Bona swore never to let Yeoreum feel that pain and helplessness of crying alone.

And in spite of that, Bona had forgotten. 

"Sorry captain, I won't be going today," Bona shuts the laptop close after unplugging the hard drive from it while plainly declaring her plan to Sojung.

"Yahh! But you're the vice-captain!" Sojung stands up, protesting, when Bona does.

"Xuanyi can take that spot today!" Bona shouts a reply as she hurriedly disappears into the bedroom, and reappearing after a minute with a backpack in hand. "Let me be home for the weekend," her request sounds more like a statement, when she walks to the door and slips on her shoes.

"It's still Friday," Sojung states, "and cheer practice isn't even gonna end very late!" and protests, but internally already giving up on discussing the matter with Bona.

"See you on Monday!" Bona says and waves before leaving.

"See you," she hears Sojung say after a sigh.

Bona closes the door and rushes off. While her legs take her to the bus stop, thoughts run in her head about how she had given up time with her sister, that she had taken for granted, for a fulfilling student life- for her own tiny dreams of living the best of her last years as a teenager. She wonders what she's missed about watching Yeoreum turn into one. Her feet impatiently tap the ground as she glances out every ten seconds for any sign of an arriving bus that takes her home.

"Unnie, will I be as tall as you one day?" Yeoreum asks, looking up to Bona, as they are walking home from errands at the supermarket one Sunday.

Bona chuckles, "Well I've stopped growing, so maybe."

"Alright, I can't wait to grow up," Yeoreum smiles.

"Don't grow up too fast!" is the older sister's immediate response. 

"Why!" Yeoreum doesn't get it.

"Then unnie can protect you a little longer," Bona whispers.

Yeoreum stops in her tracks, "Did unnie say something?"

Bona shakes her head, "Nothing."

When Yeoreum returns home, weary from her long day at school, Bona stands up and welcomes her in silence, with simply just looks in her eyes. Bona feels rather puzzled at Yeoreum's appearance, not having seen this high-schooler Yeoreum ever before. Bona's heart swells; just how much has she grown?

"Un...nie?" Yeoreum's calls in a slur, equally surprised.

Bona doesn't care that she's showered, or that Yeoreum's all sticky. Tears form in her eyes as Bona rushes over and wraps Yeoreum in a hug. 

"What's this for?" Yeoreum's voice cracks.

Bona stays silent as she tightly holds onto Yeoreum, who has now barely any height difference from her.

"You're growing up to fast," she tries to speak, but chokes on a sob.

"You just haven't been seeing me grow," Yeoreum replies.

"You should've waited for me," Bona protests, releasing the hug with tears streaming down her cheeks.

Yeoreum scowls as tears flow endlessly from her eyes as well. "I waited!" she wails.

"Now you can stop waiting, I'm here," Bona tries to smile. "Mian, Yeoreum-ah, for making you wait."

Yeoreum shakes her head. "You don't have to be present to be protecting me all the time," she answers, "you're inside here," Yeoreum brings a hand up to where her heart is beating.