Actions

Work Header

Rating:
Archive Warning:
Categories:
Fandom:
Relationships:
Characters:
Additional Tags:
Language:
English
Stats:
Published:
2025-07-12
Updated:
2025-12-24
Words:
19,593
Chapters:
5/?
Comments:
14
Kudos:
98
Bookmarks:
10
Hits:
834

Social Day: The Theme Park Adventures of The Armed Detective Agency and Port Mafia

Summary:

When the Armed Detective Agency and the Port Mafia receive VIP passes to a newly renovated theme park, they never expect to pick the same day to go and run into each other…

But of course, they do.

Atsushi, Kyouka, Lucy, and Akutagawa team up to fight a bomber terrorizing 4D moviegoers. Kunikida and Yosano solve puzzles to get closer to the truth. Poe, Ranpo, Mushitaro, and Kajii try to find hidden bombs around the theme park. Higuchi and Gin run into Aya who is there to assist her new colleagues. Dazai works with a mysterious femme fatale. And Kenji and Chuuya team up to face their fears.

Notes:

(See the end of the work for notes.)

Chapter 1: We are VIP Guests at Magical Kingdom

Summary:

Kenji is having an incredibly good day at the agency and it was made even better when they received VIP passes, courtesy of a past client. Upon arriving at the theme park, the agency members run into members of Kenji's fan club. Meanwhile, the Port Mafia, who are also invited to the renovated theme park, arrive wearing casual clothes... Well, "casual" according to them, at least...

Chapter Text

 



For Miyazawa Kenji, every day was a good day. 

That day was warm and sunny. His plants were thriving and growing strong. He had a nice snack of three beef bowls, all before lunch…  And most importantly, he had the weekend to look forward to! 

Earlier that week, the Armed Detective Agency received VIP passes for Magical Kingdom, a newly renovated theme park. They were given by one of their clients, a rich heiress who now owned the establishment. 

“So those are the invites to Magical Kingdom, huh?” Yosano looked over Kunikida’s shoulder. 

On Kunikida Doppo’s desk were several gold-colored envelopes with the names of the agency members printed in English. 

“Suehiro Tecchou and the Hunting Dogs were also given their invites, as thanks for Suehiro-kun’s part in helping us during the Sky Casino Masquerade event.”

“I remember now… That’s when you boys played hosts and saved that heiress and all the rich guests,” Yosano said with a twinkle in her eye, remembering the scandalous affair. 

“It was a job and nothing more.” Kunikida pushed his glasses back, willing every cell in his body not to blush as he remembered the details of the case. 

He showed Yosano the screen of his laptop, where a spreadsheet was open. 

“I created a table that mapped out all our available times, down to the hour. And though there is no day in which all of us are available, the ideal day is this weekend, Saturday.”

Kenji perked up when he heard about the upcoming company trip. 

“Are we really going this weekend? I’ve never been to a theme park before!” 

Edogawa Ranpo, who was snacking at his desk, joined in the conversation. “And we get free food with our VIP passes, right?” 

Kunikida read through his invitation. “Up to a certain amount, yes.” 

“Poe-kun and Mushi-kun are invited too?” Ranpo asked while he munched on some cookies. “They helped with that Masquerade case after all and many other cases since.” 

Kunikida stood up from his desk and gave three envelopes to Ranpo to give to his friends and part-time assistants. Before Kunikida returned to his desk, he saw that Yosano had already anticipated his next move — she was placing the other invites on the desks of the respective employees. 

The former teacher gave a slight nod to the doctor, who winked back. 

Most of the agency members were not in the office that day because they had been swamped with many cases after the Decay of Angels case. After gaining worldwide notoriety as wrongfully accused terrorists, the agency also saved the world, giving them hero status. 

This was shortly followed by the reopening of the Sky Casino, which their new part-timer Sigma runs. Of course, the government allowed the former Decay of Angels member to continue operating the casino on the condition that he worked for them and the agency whenever the need arose. 

And for that event, the men of the Armed Detective Agency and Suehiro Tecchou were invited as hosts for a host club event and they also doubled as bodyguards for VIP customers. And when another attack ensued, the agency members saved the day once again. 

“Yay! We’re going to a theme park!” Kenji exclaimed as he held the invitation with his two hands. “The city sure is awesome!!!”

 

***

 

Magical Kingdom was situated at the border of Yokohama. Everyone who stepped into its gates felt like they were being transported to strange and fanciful worlds. The park was divided into several sectors — Medieval Madness, Wild Wild Wild West, Galactic Zone, Jungle Fever, Halloween Town, and Broadway Avenue. 

The entrance opened to Broadway Avenue where visitors could buy souvenirs, watch musical plays and puppet shows in the indoor theaters, and more. 

This was where most of the admin offices were located and where the agency exchanged their invites to smart watches, indicating their VIP status. They simply needed to tap their watches on the scanners of rides and food stalls. 

Kunikida informed the staff that they were expecting more people later that afternoon — the other agency members who were occupied that morning. 

“Except Dazai! When I asked him if he was coming, he said, ‘Maybe, maybe not!’” 

“Kunikida-san! Calm down!” Atsushi tried to placate his senior. “Perhaps Dazai-san is still busy with his solo mission!” 

“Besides, this isn’t even an official company event,” Yosano added. 

Kunikida sighed before taking in deep breaths. “This may be for the best. Dazai may get into all sorts of trouble while we’re here!” 

As they were exiting the admin offices, the agency members who could make it that morning — Miyazawa Kenji, Kunikida Doppo, Yosano Akiko, Edogawa Ranpo, Nakajima Atsushi, and Kyouka Izumi — heard a screeching sound. 

“IT’S MIYAZAWA KENJI!!!”

“KENJI!!! KENJI!!!”

“AAAAHHHHHH!!!!”

Suddenly, a group of four middle school-aged girls rushed towards the detectives. 

“Hello, Armed Detective Agency,” said the tallest girl with long black hair that fell to her waist. “My name is Nagase Kiyoko. I am a junior high school student and I am the President of the Society of Friends of Miyazawa Kenji!” 

The other girls made their introductions. There was Nomachi Teiko, the Secretary. She wore round glasses that covered almost half her face. Then there was Suzuki Mikki, the Treasurer, a short girl with a bob, the only one who looked like she didn’t want to be there. And finally, a girl with curly blonde hair who simply introduced herself as Fuji, the Vice-President. 

Throughout it, the rest of the agency was too stunned to speak. Only Kenji was all smiles. 

“It’s nice to see you again, Kiyoko-chan, Teo-chan, Fuji-chan,” he turned to the girl whose arms were crossed in front of her. “You too, Mikki-chan!” 

“I’m only here because Teiko is the club secretary and I can’t allow her to wander off alone, okay?” 

Teiko put an arm around her friend. “She doesn’t mean that, Kenji-san! She also enjoys being in the club!” 

“So this is a fan club?! This was not authorized!!!” Kunikida said. 

“But we did get authorization!” The girl called Kiyoko said. “We were in touch with one of your staff members Naomi-san, who also runs the social media pages of the Armed Detective Agency!”

“Social media what?!” Kunikida’s jaw was on the floor. 

“Oh, I heard about this from Naomi!” Atsushi said. “You didn’t know about it, Kunikida?”

“I knew about it too! Poe-kun follows the account,” Ranpo said. “I heard we get clients from the pages. Naomi handles the inquiries we get from the social media pages then she forwards the requests to the official hotline.” 

Kyouka stepped forward and clicked several times on her phone screen before showing Kunikida a page that contained photos of the Armed Detective Agency. Most of them are group photos during official events, but there are also solo photos of each of the members, even Kunikida. 

Kunikida snatched the phone from Kyouka. “Hey, when was this photo taken?!” 

It was the side profile of Kunikida while he was typing on his laptop. He clicked on the photo and comments appeared underneath. The girls from Kenji’s fan club and the agency members all moved behind Kunikida to read the comments. 

 

“Kunikida-sensei is so handsome!” 

 

“I am a former student of Kunikida-sensei. He was strict but kind. I wish him the best of luck in the agency!” 

 

“This is the man who helped us with a case concerning our business. He was very professional. Thank you, sir.” 

 

“YOU GO ADA! THAT WHOLE DECAY OF ANGELS BUSINESS IS OVER! YOURE OUR HEROES! DONT MIND THE HATERS!” 

 

“This is the man I like in the commercial for the Sky Casino!” 

 

“That’s my teacher yo!”

 

“He still looks so serious!” 

 

“I want to be those glasses!”

 

“I want to be that chair…” 



And then the comments got weirder. Kunikida returned the phone to Kyouka. “Well, if it’s helping us get clients…” 

“Your face is really red right now, Kunikida-san!” Kenji wondered out loud.

The former teacher felt his face getting hot for some reason. “No…! No, it’s not!” 

“Is it because of the comments from the girls?” Atsushi asked. “Some of them are quite aggressive, to be honest…” 

“Will you look at that! Even Kunikida has fans!!!” Ranpo joined in the teasing. 

“Maybe you have a fan club you don’t know about, Kunikida!” Yosano chimed in. 

“Stop it!” Kunikida said. “Anyway, I noticed that everyone except Dazai had a solo photo on the page - ”

“Oh… About that…” Atsushi and Kyouka exchanged glances. And with a hesitant tone, he continued. “I heard that when we post about Dazai-san, we get lots of comments from girls asking where he is!” 

“Angry comments,” Kyouka emphasized. “I follow the page and I report them.”

The fan girls all nodded, saying they see the comments too since they also follow the page.

“… So Naomi ends up removing the photos,” Atsushi continued. 

“Not surprised!” Ranpo said, shrugging. 

“You just need a better manager!” The fan club president said. “Look at our page!” 

She showed them the homepage of the same photo app. Kenji’s Fan Club page has over 200,000 followers. It was 190,000 more than the agency’s page. 

A lot of the photos were of Kenji in action as he carried heavy objects. Other shots are of him with fans or groups of girls. 

“Wow, Kenji! I never realized how popular you are! There are even some foreigners who take photos with you…” Yosano looked impressed. Like Kunikida, it was her first time seeing the social media pages. 

“We also get inquiries from the page and we forward them to Naomi-san,” The secretary Teiko said. 

“We’re not paying you for doing this?” Kunikida asked the girls. 

“We do it for the love of Kenji-kun, of course!” Kiyoko said. The rest of the girls nodded, except Mikki, who simply rolled her eyes. 

“Our monthly fan club meeting is enough compensation!” Fuji said. 

“You city girls are too kind!” Kenji smiled at them and the girls swooned.

“As Deputy Director of the Armed Detective Agency, allow me to formally thank you anyway,” Kunikida said, bowing. 

Then Kiyoko smiled with a mad glint in her eye. “Perhaps you can thank us by allowing us to tag along so we can take photos of Kenji and the agency here in the park! They would make for really good photos! We will also send photos of the group to Naomi-san in case she needs it for future posts.”

Kunikida turned to Kenji. “Are you okay with this, Kenji?”

Kenji nodded with his usual smiling face. “Of course! I want to send Tecchou-san some cool photos too since he couldn’t make it today!” 

“And you’re all okay with this?” He asked the other agency members. The rest nodded or muttered their version of agreement. 

“I guess, as long as they don’t get in the way,” Yosano said. “And make sure to get my good side, okay?” 

The girls squealed in delight. “Thank you very much!!!”  Kiyoko bowed and the others followed suit.

Ranpo pointed to the direction of the rides awaiting them. “Well, now that introductions are all done and while we wait for others, shall we go try the rides?” 

 

***

 

The Medieval Madness sector of the park was designed to look like Europe in olden times — there were castles and restaurants designed like taverns. The street actors were also dressed like princes, princesses, and wizards, taking photos with the excited children. 

In front of the biggest castle was a fake moat and a picnic ground where visitors could rest and relax. One group stood out from the rest, looking like a dysfunctional family. 

“Elise-chan!!! Please! Just one photo and pose for me, please!!!”

“You sound like a creepy stalker, Rintarou!” 

“But it’s for your social media page!!!” 

The Port Mafia’s boss, Ougai Mori, together with several members of the mafia, also received VIP passes from the same heiress, the owner of the park. 

“Boss, when you asked to go here and told us to dress casually, we thought it was a covert mission…” 

Port mafia executive Nakahara Chuuya looked around suspiciously, disappointed that the other mafia members’ understanding of “casual” was quite different from one another and society’s definition. Akutagawa Ryunosuke wore an all-black ensemble, fit for a funeral and not a theme park. Higuchi Ichiyo wore what he could only describe as a milkmaid costume. Motojiro Kajii had his usual lab gown, except it looked shabbier than usual. Hirotsu Ryuro donned a military outfit. Only Gin looked passable, with a simple white dress. 

“Oh?” Mori looked stumped. “You thought this was a covert mission?” 

“So, boss? Is there anything?” Chuuya whispered as he inserted both hands in the pockets of his loose red overshirt. It covered a plain white tee and part of his black, casual jeans. 

Instead of his usual hat, he wore a simple black baseball cap. 

Mori kept taking photos of Elise with his phone despite the little girl trying to shove the phone away from her face. 

“I wanted you guys to have fun,” Mori finally answered Chuuya after a few failed attempts getting Elise to sit down. “We got these tickets for free, after all. And we have you to thank, of course. Since you also protected the princess from that Masquerade event.” 

“This isn’t a mission?” Kajii asked, looking around at the equally confused faces of his colleagues. 

Out of everyone in the group, only one person was ecstatic about this: Higuchi. 

This is my chance to be alone with Akutagawa-san! And maybe warm up to Gin too, she thought.

Akutagawa coughed. “Our mission is to have fun today. Understood. Where shall we start?”

“Well, we don’t have to stick to each other the whole day,” Chuuya said. “You guys go ‘head. I’ll stick with the boss and make sure he’s safe and all.” 

Hirotsu put an arm on Chuuya’s shoulder. “Chuuya-san, you go with them. I can look after the boss.” 

Chuuya glanced at the tavern nearest the picnic. When they passed by it, he noticed the sign outside, boasting of a selection of alcohol. 

“Ya sure, old man?” The gravity manipulator asked hesitantly. 

Hirotsu nodded encouragingly. “It’s because of your hard work that we are here, after all.” 

“Well, if you’re sure…” 

“Go, Chuuya-san…” 

He bowed to Hirotsu and mentioned to everyone that they could meet at the main food court for lunch. The others agreed before dispersing. Kajii went on his own, mumbling to himself that the Laboratory of Horrors would be cool to check out. The Akutagawa siblings headed off to the Wild Wild Wild West, followed closely by Higuchi. 

Chuuya headed straight to the tavern. “Well, it can be a good day… As long as that Dazai isn’t around…” 

 

***

 

Just a few meters away from the picnic grounds where Mori was taking photos of Elise was a control center. 

In there, a theme park staff member watched the real-time security footage of the zone. Another staff member smirked menacingly as he watched the happy faces of the park visitors. Only he knew of the explosives, ready to be deployed and hidden in the next room…



NEXT CHAPTER: THE MORE, THE MERRIER! WE MEET OUR OLD AND NEW FRIENDS!