Disclaimer: Of course I don't own Bungo Stray Dogs, its characters, or the franchise. This is fanfiction after all.
Story: Atsushi continues to bond and connect with her newfound father, and slowly begins to be introduced and meet her new family. Francis just continues to support and be a good signficant other, while being dragged into the family matters himself. Agency and Guild antics included in that. In other words, moments where Atsushi and her families develop together and their relationships grow.
Set as a slice of life, future-ish fic, set somewhere after season 3 of the anime.
Spoilers: Maybe.
Warnings: Age disparity. Mild implied sexual situations.
Pairings: Francis Fitzgerald/Fem!Atsushi

Family
Chapter Three: Big Sister

Riku scowled heavily, his arms angrily crossed together as he glared off to the side. This wasn't his fault. Stupid Touya had said something stupid and had purposely tripped Tamaki, making Riku's baby brother cry. So what if he'd punched Touya in the face for it? It was his fault!

But now he was in the Principal's office!

His dad was busy and probably couldn't come; same with his mother, who was helping his dad on his campaign. He had other family, but wasn't close to them. Who could come in for him, like Touya's parents —

"We're still trying to reach either your Okaa-san or Otou-san, Fujiwara-kun, but —"

"Wait, wait!" Riku hurriedly stood up. "Call my Onee-san! She'll come!"

Actually, he didn't really know that and he didn't really know how to contact her either. Plus, she just met him that one time and all and he wasn't sure if she liked him yet. But it was better than letting his parents know he'd gotten into trouble and they didn't have to be called up and be bothered by this anyway!

"What is her number then, Fujiwara-kun?" the school secretary, Mrs. Tsukino, asked, smiling at him encouragingly.

He flushed red and fidgeted. "Um, um…I don't know her number. But I do know where she works!" he hurried to add.

"That'll work then," Mrs. Tsukino uncertainly said. "Do you know her work number or just where she works?"

"Just where she works," Riku blushed even harder. "Um…she works at the Armed Detective Agency."

Mrs. Tsukino paused, looking even more uncertain. She gave him a glance before picking up the phone after searching the Agency's number. "Hello, is this the Armed Detective Agency? No, no, there isn't an issue. This is Yokohama International —I have a student asking for his sister? He says she works there. I believe her name is…" She looked to him and he told her quickly 'Nakajima Atsushi', which she repeated on the phone. "Yes, thank you."

She held out the phone to him. "They're retrieving her right now, Fujiwara-kun."

He nervously took the phone and held it up to his ear, waiting to see if she'd come to it. He bit his lip, thinking he was being dumb, when he heard her voice.

"Hello?"

"Onee-san!" he excitedly greeted. "I didn't think you'd come!"

"Riku-kun? What's wrong? Did something happen to Otou-san?"

He turned red again, knowing this had been probably out of the blue and that it'd be strange for him to call her. "No. Onee-san, I got in trouble at school and my parents aren't picking up, so I thought I could call you instead," he rushed to say. Then…"I didn't want Okaa-san or Otou-san to know I got in trouble anyway," he said in a hush, glancing at Mrs. Tsukino. "I don't want to get into trouble at home too!"

He heard her laugh quietly, pretty like wind chimes. "Okay then…Do I need to come there?"

"Please?"

"I'll be there soon then."

After she hung up, he felt much better. Then he handed the phone back to Mrs. Tsukino and looked at her sheepishly.

"Thanks, Mrs. Tsukino," now all Riku had to do was wait.

When she came soon after, Riku couldn't believe it. Even though she said she'd come, he still hadn't been sure. And now she was here and she looked so pretty and cool and wow —he hadn't realized how kind of tall she was. Well, not as tall as that gaijin his father said was her boyfriend, but she was super tall for a girl. She was taller than Okaa-san and nearly as tall as Otou-san!

"Onee-san!" he greeted excitedly, bouncing in his seat. "You came!"

She smiled sweetly at him and headed over and the both of them ignored the curious secretary watching them. He couldn't help bouncing over to her and grinned when she rubbed his head affectionately. Was this what it was like having an older sister? Or just an affectionate older sibling at all? Haru wasn't like this at all, even though he could be protective too.

Actually, even though he knew his family loved him, all of them weren't big on affection either. His dad and older brother were really kind of quiet and serious, and his baby brother was just a baby kid (who was a weird quiet one too). Even his mom was pretty traditional and restrained most times.

"I did. Now who do I have to talk to?" she smiled at him and he looked shyly over at Mrs. Tsukino, though he couldn't help lean in close to his sister and draw in her warmth.

"That's Mrs. Tsukino —Mrs. 'cause she married an American," he whispered to her, making both women smile. "She's going to let us know when we can see the Principal. Touya-teme and his parents are in there right now."

"Language," she said, still absentmindedly brushing his hair with her hand. She directed her focus on Mrs. Tsukino then. "Can you tell me what Riku-kun was called in for, Mrs. Tsukino?"

"Certainly," Mrs. Tsukino said and explained the situation to her.

Atsushi frowned and Riku inwardly cringed. He wondered if she was going to lecture him now or be upset with him.

"I see…So that's what happened," she hmmed before turning to him. "Riku-kun, I hope you understand what you did wrong?"

He flinched and toed the floor, nodding a little after. "I shouldn't have punched him…even though he deserved it," he muttered that last part.

Riku glanced up at her and saw her lips twitch up, making him relax a bit. She patted his shoulder.

"As long as you understand that," she told him. The Principal's door opened then, causing them to turn towards it. Atsushi pulled him closer to her, making him straighten up and grin inside.

"I sure hope that child is punished or I will be pulling my donations from this school —"

"Ahem," Atsushi loudly said and Riku was inwardly awed and slightly scared at the cooled look and icy glare that came over his sister's face.

Touya and his father and his mother, along with the Principal, turned quickly to them, caught off guard by the new presence. The smug look on Touya's face became unsure, but Touya's father and mother looked haughty and condescending towards them.

"And who is this?" Touya's father sneered.

"I believe it's only polite to introduce oneself first," Atsushi said coldly, drawing herself to her full height and amazingly the tallest person in the room. "But as you insist, I'm Nakajima Atsushi, Riku's sister," she bowed elegantly, very polite.

Then she straightened up and lifted her chin at them, seeing as Touya's parents looked even more condescending at her introduction.

Atsushi smiled sharply, eyes closed.

"And also a member of the Armed Detective Agency, so please feel free to contact us and utilize our services," she said, all the while smiling and taking out her badge. "We deal with all sorts of cases —robbery, hostages, hold ups, bribery…"

Touya's parents and the Principal flinched, making Riku look between them and his sister in confusion.

Atsushi gently patted Riku's arm again. "My otouto understands what he did was wrong —" Riku nodded hurriedly, watching his sister with wide eyes. "We both understand he will be punished accordingly. However, I do hope that, given the school's zero bullying policy…that also follows through for all parties…"

She glanced at Touya and kept smiling. "After all, we don't want any child in school to turn out to be criminals," she said, still smiling and yet somehow there was something menacing about her.

"O-onee-san," Riku muttered, gaping at her.

But he was entirely glad to see Touya look terrified. So did all the other grownups around them actually.

It was kind of funny.

Started 7/15/21 — Completed 6/18/22

A/n: Geez, this has been written for the longest time; just haven't been motivated and forgot about it XD

Quick Points:

1. Psst. Yokohama International is real. I did actual research for this nonsense XD

2. That's right, 'Mrs. Tsukino' and her American husband is a nod to my Sailor MoonxWeiss Kruz crossover fic :)