Summary: Atobe Keigo has always kept a watchful eye over his little sister, Nao. But when she decides to transfer to Rikkai Dai, he's finding it more and more difficult to keep tabs on her. What's worse is that she's taken a liking to Marui and his sugar tooth is the last thing Atobe thinks his diabetic sister needs. MaruixOC (with a dash of jealous Atobe)

- Prologue -

With as much speed as her legs could muster, Atobe Nao strode quickly towards the tennis courts with her dog in tow. It was only the first week of school and yet she already felt tired. Having to juggle her new school life and her old one was exhausting, but that was the condition she'd agreed to in order to change schools. So every day she found herself trudging back to Hyotei Academy so she and her brother could go home together after tennis practice.

"Excuse me," she huffed, weaving her way through the hoards of people crowding the courts. As always, there was a huge turnout during the first week. Male students from every grade were there to join the tennis team, along with their female counterparts who typically had other motivations for showing up. However, what made the situation worse was the fact that there was no order to the chaos. The spectators were all just crammed into the bleachers or pressed up against the chain link fencing. As a result, Nao could see the crowd growing more and more agitated by the second.

"You're on my skirt, freshman," one senior said angrily, glaring at the first year sitting next to her. The first year apologized profusely and moved over a couple of inches to the left.

Shaking her head, Nao continued on her way. She had more important things to do than to settle quarrels between the club's hordes of fans. Her brother was waiting, and Nao knew better than anyone not to let him wait too long.

It didn't take long for her to break through the sea of students circling the courts. After all, they pretty much parted willingly upon recognizing who she was. Of course their whispers didn't go unnoticed, and Nao cringed inwardly when she heard some of her peer's comments.

"She's here again? I thought she transferred schools," one girl told her friend, shooting Nao a dirty look.

"I know. I hoped the tennis team would shift their attention to other people, and like maybe get girlfriends or something. I guess that's not happening now that she's back," the other girl replied, following Nao with beady eyes as she passed by. "She just likes to be fawned over."

Silently, Nao just kept her head down and kept walking. The last thing she needed was to stir up a fight and anger her brother even more than she already had. It wasn't until she slammed full force into one of the regulars did she stop and look up.

"Shishido-kun," she breathed in relief. "I'm glad I ran into you. I just didn't mean it so literally."

"Well, we were supposed to see you half an hour ago," Shishido told her sternly, simultaneously offering to take her heavy school bag from her. "You know Atobe doesn't like it when you wander off on your own." The regulars had been on the look out for her since practice began. Ever since the news broke of her transfer, Atobe had been a little on edge. He hadn't exactly been keen on his little sister studying somewhere else, and it was showing. Heck, practically everyone was feeling uneasy, especially the regulars.

"Technically, I'm never actually on my own," Nao smiled, pointing to her constant companion, Jun. The yellow Labrador wagged its tail happily as his owner patted him on the top of his head. "Besides, it's not like breaking through the barrier of people surrounding the courts was an easy thing to do."

Nothing about the club had changed much since last year. The majority of the new club members weren't serious about tennis. They were just here for the fans and popularity that came along with being somehow associated with the regulars.

"Well, I guess it's okay as long as you're here now," Shishido sighed, running his hand through his long brown hair. He'd always thought Atobe's younger sister was unlike anyone he'd ever met. She was petite and easily manhandled, but was strong-willed too, especially when it came to her brother. He was often in awe of how patient Atobe was with her. She frustrated him on a daily basis and loved pushing her big brother's buttons. But she was his only sister, and for that very reason Atobe tolerated her. "The captain has been a little restless, so you'd better get over there."

"Alright," Nao said. "Where is he?"

Shishido pointed across the court to a cluster of people dressed in the tennis club uniform. Her brother stood tall in the center as he supervised a drill. All around him, freshmen were doing sprints. There were ten of them spread out across the baseline. When Atobe gave the signal, they took off as fast as they could. After the first two reps, they had all slowed down a noticeable amount until they were practically dragging themselves back and forth. Atobe didn't look impressed, and his expression hardened further when he noticed his little sister strolling towards him fifteen minutes late.

"Where have you been?" The captain of the Hyotei tennis club demanded. His voice boomed through the courts, silencing all those around him. For a moment, everyone turned to see the object of his fury. He rarely lost his composure, so it came as a surprise for many. However, once they saw it was Nao he was speaking to, they returned to whatever they were previously doing. They knew better than to interfere when the two siblings were fighting.

Blissfully ignorant to her brother's anger, the young girl smirked. "Where I went doesn't matter," she said, turning to face him. "But if it's bothering you so much, I stopped by the grocery store for some treats."

Atobe frowned. "No you didn't. You're not like that," he said.

Nao chuckled. "For Jun, not me," she specified, grinning ear to ear. "Baka!"

The king of Hyotei shook his head. He'd intended to scold his sister a little longer, but his anger dissipated the instant he saw her smile. All last year she'd looked miserable at Hyotei, but now she seemed a lot happier at Rikkai Dai.

"He's been working all day, so I thought he deserved a treat," Nao pointed out, reminding her older brother that Jun had a job to do. He was her medical detection dog, charged with detecting changes in her blood sugar levels that could endanger her life as a diabetic.

"Well, if that's the case, just make sure to call me beforehand next time," Atobe said calmly.

"Will do!"

"Anyways, practice is almost finished. So wait until then and we can go home together," Atobe said, turning his attention back to practice.

"Wait! Onii-chan, where's Akutagawa-senpai?" Nao asked, grabbing onto the bottom of his jersey.

"Sleeping in the stands. Why?" he asked curiously. His sister rarely sought out his friends or any of her upperclassmen.

Grinning devilishly, knowing full well how much it would bother her brother, Nao didn't hold back. "Because I need to ask him something about a boy."

The color drained from Atobe's face almost instantly.

So how was the prologue? Please let me know what you think. I appreciate all reviews and it drives me to update faster.