It was a rare, quiet Sunday morning. Kazuki sat at the dining table with a fresh cup of coffee, savoring the peacefulness of the day. But, as expected, the calm didn't last long.
"Good morning, Onii-chan!" Aoi's voice rang out as she trudged into the kitchen, her hair still messy from sleep, and she plopped down on the chair across from him, rubbing her eyes.
Kazuki chuckled, setting his mug down. "Rough night? You look like you barely slept."
Aoi yawned and gave him a pout. "It's because I was up late, studying! All that school homework doesn't just disappear on its own, you know."
Kazuki raised an eyebrow, giving her a teasing look. "Didn't you leave most of it until the last minute?"
Aoi puffed out her cheeks indignantly. "Hey! I finished it, didn't I?"
Kazuki shook his head with a small smile. "Barely. If it weren't for me helping you, you'd probably still be working on it."
"Yeah, yeah." She grinned sheepishly, reaching for the box of cereal on the table. "Well, thanks for the help anyway, Onii-chan. You're the best."
"Flattery won't get you out of doing chores," Kazuki replied, smirking as he took another sip of coffee.
Aoi stuck her tongue out at him, then began pouring herself a bowl of cereal. As she munched, she looked around, her eyes brightening with an idea. "Hey, Onii-chan, since it's such a lazy day, let's do something fun together!"
Kazuki raised an eyebrow. "Like what?"
Aoi's face lit up, and she began listing ideas enthusiastically. "We could play video games, go to the park, or maybe even do a cooking challenge! Ooh, or we could invite Shizuka and have a mini movie marathon!"
Kazuki chuckled. "Sounds like you've got a full list planned out. But aren't you still tired?"
Aoi waved her hand dismissively. "Nah, once I eat, I'll be good to go!" She finished her cereal in record time and looked at Kazuki expectantly. "So, which one are we doing first?"
Kazuki sighed, feigning exasperation. "Alright, let's play some games. Just don't get mad when I beat you again."
Aoi's eyes sparkled with a competitive gleam. "Oh, please, Onii-chan. I'm totally beating you today!"
---
The two of them spent the next hour in a fierce gaming battle. Every time Kazuki won a round, Aoi would groan, complaining that he was using "unfair moves." But when she managed to win one round, she jumped up, cheering like she'd just conquered the world.
"Ha! Take that, Onii-chan! Looks like the student has surpassed the master!" Aoi crowed, punching the air triumphantly.
Kazuki laughed, shaking his head. "You got lucky, that's all."
"Oh, is that so?" she smirked, picking up the controller again. "Then let's go again! I'm on a winning streak!"
Kazuki obliged, and they continued playing, laughter and teasing filling the room. Even though she lost more rounds than she won, Aoi's enthusiasm never wavered. She kept challenging him, determined to prove herself as the "ultimate gaming champion."
---
After a few more rounds, they decided to take a break, both of them flopping onto the couch, exhausted from their intense gaming session.
Kazuki glanced over at Aoi, who was staring at the ceiling with a satisfied smile. "You're not bad, Aoi. Maybe with a little more practice, you'll actually beat me for real."
Aoi grinned, nudging him with her elbow. "You just wait, Onii-chan. Next time, I'll totally crush you."
He chuckled, ruffling her hair. "Sure, keep dreaming."
Aoi swatted his hand away, laughing. "Stop messing up my hair!" She quickly fixed her hair, then looked at him thoughtfully. "Hey, Onii-chan, can we really invite Shizuka for that movie marathon sometime?"
Kazuki felt a slight blush creeping up his cheeks but nodded. "Yeah, I'm sure she'd be up for it."
Aoi giggled, noticing his reaction. "Ooh, someone's getting embarrassed~."
Kazuki rolled his eyes, trying to act nonchalant. "I'm not embarrassed."
"Right, right," Aoi teased, smirking. "You and Shizuka are so obvious. It's cute, though."
Kazuki shook his head, hiding a smile. "Alright, enough teasing."
Aoi laughed, leaning back with a contented sigh. "Today was fun, Onii-chan. We should do this more often."
Kazuki smiled, feeling a warm sense of happiness. "Yeah, we should."
They sat there in comfortable silence, enjoying the peacefulness of the day. It was moments like these that made Kazuki grateful for his little sister, even if she drove him crazy sometimes.