Unexpected jealousy

( In this story you and Chuuya are friends but you always call him Chuu-nii or Chuu since he was like a big brother to you. The same goes for Chuuya as he always call you kitty because you love receiving headpats from him. Btw the reader here is oblivious so enjoy🤭)

At your apartment

You were humming to yourself while trying to get ready for work. Even though working at the office can be a bit dreary due to the amount of paperwork and sudden attacks from other mafia groups in the area, you're still happy to go there since you get to meet everyone and not to mention that after work today you will be having dinner with Chuuya. You were excited to meet Chuuya again cuz both of you were so busy with work that you barely see each other these days After you got ready, you received a phone call from none other than your suicidal maniac senpai. You then sighed and picked up the call knowing damn well that Dazai was up to no good.

"Moshi-moshi~ Dazai-senpai. If you're calling me to invite me for a double suicide, then I have to decline cuz I still appreciate my life" you said in a bored tone. "Ahh! (Y/n)-chan you're still cold as ever! There's nothing wrong with commiting a double suicide with a handsome man as me you know" said Dazai.

If you could see his face then you can definitely know that he was smirking through that damn call. Even though you wanted to end that call right away, you had to listen to him talk until he wants to stop talking. Wanna know why? Cuz he will keep calling you until you finally answer him. The last time you ignored his call, it ended up you getting a big headache and boy you finally understood to why Kunikida was losing his braincells whenever he had to go on any missions with him. So you decided to cut to the chase cuz you were gonna be late for work and didn't want to get an earful from Kunikida.

"What did you do now Dazai-senpai?" you asked sternly. "Um... I need a little bit of help here (y/n)-chan. Can you come outside of your apartment?" asked Dazai nervously. Whenever you used a stern tone during a talk, Dazai knows that he was screwed. You just sighed and went outside only to see that suicidal, yet idiotic senpai of yours inside a barrel.

You just sweatdropped at this scene cuz you weren't sure whether to be rude or polite to him at that moment. Tbh you wanted to say that he looked like an idiot being stuck inside that barrel, but at the same time you already have to see him do these kinds of stunts many times already. "I swear I'm gonna be late for work cuz of him! you internally screamed while ruffling your hair angrily. You just glared at Dazai and when he made eye contact with you he became pale. "H-Hi (y/n)-chan. Lovely day it is today right?" he asked nervously. You went down from your apartment and went to the barrel. You then just kicked the barrel until Dazai rolled out of it while holding his head due to getting it hurt. You walked up to Dazai and just knelt down on the ground to meet his eye level. You just stared at him while just stared at you. Both of you had that staring contest for a minute until you punched his head really hard.

"ITAI! Why did you do that for?" asked Dazai while he rubbed the area where you had punched him. " Oh I don't know. Maybe you know the answer to it senpai" you said with a hint of anger and danger in it.

This is how you glared at Dazai. Minus the blood from the face. Credits to the artist of this pic btw.

"Hehe... I just wanted to try a new suicide method. Didn't expect it to fail" Dazai said. You really wanted to hit his again and then you realized you had to get to work asap. " I'll scold you later so right now let's go to the office before Kunikida-senpai yells at the both us" you said. "Ok!" Dazai said happily while giving you a thumbs up. " Seriously why do you always try to make problems first thing in the morning? You gotta give me a break you senpai." you complained to him. "Hmm.. I guess it's that I just want your attention (y/n)-chan~❤️." he said flirtatiously. You just looked at him weirdly and raised your eyebrow. It was obvious that you were oblivious about his flirtations that he said to you. You just scoffed and said " Enough flirting already. Let's just go already". You then walked really fast leaving Dazai behind leaving him in shock at your obliviousness.

Let's just say that this is how Dazai looked astonished.

Dazai pov

"She didn't get it again" said Dazai as he just sighed at your walking figure. The thing is Dazai here has a crush on you for quite some time and he tried everything to get your attention. Literally everything to get you to notice his big crush on you. But alas... you never noticed because you never know when he was serious or just playing with you whenever he flirts with you or even when he confessed to you. Yup. Dazai did indeed confess to you around a few months ago,but when he remembered what had happened he felt that he should just bury a hole and live in that hole itself.

Flashback to a few months ago

You and Dazai were both walking back to the apartments when Dazai stopped you from walking which made you stop in your tracks as well. Dazai was already blushing and mustered up his courage to say what he wanted to you. "(Y/n)-chan I love you" Dazai confessed to you one evening. You just became silent. Dazai became nervous at this and was about to ask until you spoke up. " Dazai-senpai... you always say I love you to me you know. If you want to confess to the girl that you love, you need to do it with more passion." you commented on his confession. At this moment Dazai felt that his heart just froze out of shock. He didn't expect that you said that. He forgot that you were oblivious to the point that you didn't even know that he was serious about his confession towards you. Dazai just gulped his own saliva and sweatdropped. "M-maybe you're right... Thanks for the comment (y/n)-chan said Dazai as he was DESPERATELY tried to not break his character at the moment. "You're welcome senpai!" you said happily.

End of flashback

"I need to be straightforward with her and just directly confess to her. I really don't want to go through that again" said Dazai as he was shedding fake tears. It was a good thing that he fell for you, but your obliviousness is just killing him tbh.

Timeskip after work

You happily tidied up your stuff and hummed happily which made Atsushi noticed your unusual happy behaviour. "(y/n)-chan you seem happy today. Is there something going on?" he asked. " Of course! I'm finally going to be having dinner with Chuuya. We're going to have dinner at Larche cafe and since it's been so long since I met up with him. I wanna catch up with him as much as possible. Oh! I gotta go now Atsushi-kun. I don't wanna be late to meet Chuuya!" you said happily while rushing out of the door.

Atsushi pov

"Chuuya? Wait isn't that Nakahara Chuuya from Port Mafia?!" Atsushi internally screamed at the thought of you going to a dinner date with Chuuya soon. Just then Dazai came inside the office looking for (y/n). "Oh Atsushi-kun. Have you seen (y/n)-chan? I wanna talk (confess) with her about something" asked Dazai. "Wait. Why do you look so pale? Did something happen to (y/n)-chan?" asked Dazai worriedly. "D-Dazai-san... Apparently she said that she's going to have dinner with Chuuya" said Atsushi nervously. "Oh that's great then.. WAIT WHAT?! HAVE DINNER WITH THAT DWARF?!" yelled Dazai. "Yeah. She looked really happy when she talked about Chuuya tbh." said Atsushi.

Dazai looked like he was about to explode because out of all people that she could get dinner with is with that ginger haired dwarf. He gritted his teeth out of jealousy and asked Atsushi where you were. Atsushi then told him that you went to Larche cafe and Dazai sped out of the office as fast as he could. There was no way he was gonna let you have a dinner date with dwarf."I-I have never seen Dazai-san act jealous about this." said Atsushi while he sweatdropped at Dazai's actions just now.

At Larche cafe

You arrived at the cafe a bit late as you went to buy some wine for Chuuya. That guy does love wine so you thought that giving him wine would make him extra happy. You then searched for Chuuya until you felt someone patted your head. "Hey there kitty! It's been a long time since I last saw you!" said Chuuya while he grinned at you. You then just happily let Chuuya pat your head.

This is how you look like everytime you get headpats from Chuuya. (Minus the ears btw)

Unbeknownst to the both of you, Dazai was irked when he saw that physical interaction between Chuuya and you. "Seriously?! She just looks so happy and cute like that! But why is it that damn dwarf can make her like that? I need to get to the bottom of this.

A bit of timeskip cuz I'm lazy to write it too long.

After both you and Chuuya had ordered your food (including Dazai who had successful entered the cafe without the both of you noticing his presence, you then then happily talked to Chuuya. " Chuu-nii I swear it's been so long since I last saw you. Although you haven't really grown in height tbh" you cheekily said to him. "W-why you little brat! Just because I ain't tall yet doesn't mean that I ain't storing you know!" said Chuuya while trying his best to hold in his blush. "Hehe. You look so cute blushing like that Chuu-nii. You would be a hit with the girls soon~" you teased him. "Hmph! If you weren't my friend I would have flicked your forehead so hard that you would have cried by now." said Chuuya while folding the both of his arms.

Dazai was perplexed at what the both of you said. He didn't expect you to see Chuuya as a brother figure and definitely did not know anything about it, even though he knew Chuuya for quite some time during his days at the Port Mafia. He then gave out a relieved sigh until he felt that someone was giving him sharp glares. He turn around and met eye-to-eye with Chuuya who already looked irked at his appearance. "Why now out of all times?" said Dazai as he sighed. He knows that Chuuya was gonna annoy him soon so he took the liberty to get up from his seat and went to yours and Chuuya's table. You were shocked to see Dazai there and man Chuuya was not having that suicidal maniac ruin his dinner plans with you.

"Yo Chuuya~ Haven't seen you in a long time. Having a dinner date with my (y/n)-chan is it?" said Dazai playfully. Now this shocked you and made you blushed because you weren't expecting Dazai to call you his (y/n)-chan. You were about to say something when Chuuya angrily told off Dazai. " I don't see a problem with me hanging out with (y/n) you know. And since when was (y/n) yours to begin with? I didn't hear any news about her dating anyone" said Chuuya in a low tone. Both men were straing at each other dangerously and you didn't want them to cause a scene in the cafe. So you got up and pulled both of their ears before they did anything stupid.

"Ouch!" yelled both Dazai and Chuuya at the same time. They didn't expect you to pull their ears so they want to tell you off until they saw your menacing glare that bore right into their souls. They gulped because they didn't want to get screwed by you. You then sighed. " Chuu-nii can I talk with Dazai-senpai for a bit. I have some unfinished business with him" you said while having that scary tone laced in your voice. "S-sure. Make sure to not talk to long" said Chuuya nervously. "Well let's go outside for a bit senpai~" you said to Dazai. " S-sure" said Dazai nervously. DAzai knows that he's gonna get hit in the head soon so he mentally prayed that you would go easy on him.

Outside of the cafe

"So... Wanna tell me why did you follow me today? And why were you telling Chuu-nii that I was yours? You never confessed to me you know that right?" you asked him curiously. At this statement Dazai felt like a boulder fell onto him. Did you seriously just told him that he never confessed to you? (Y/n)-chan... I did confess to you a few months ago. Only you thought that I was practicing my confession back then. There was a moment of silence until you finally blushed and yelled at him embarrassingly. "W-WHAT?! WAIT! THAT CONFESSION BACK THEN WAS FOR ME?! WHY DIDN'T YOU SAID ANYTHING ABOUT IT?!" you yelled at him while trying your best to keep your composure. " That's because I didn't know that to say ok?! You just commented on my confession and what was I supposed to say?! Should I have said that the confession was for you at that time? It would have been akward!" yelled Dazai back while trying his best to not show you his red face.

You noticed that Dazai's face was so red that you couldn't believe your own obliviousness. You were about to say something when Dazai puts his fingers on your lips. "Let me say this just one more time before you say anything (y/n)-chan. I followed you here today because I thought you were going out with Chuuya, and I didn't want him to steal you from me. I was jealous that he was able to make you happy. And yes.. I-I love you a lot. That's my sincere confession to you" Dazai confessed to you.

You froze on the spot. You didn't expect the Dazai Osamu to be jealous of Chuuya. You then chuckled and blush at his confession. Dazai was about to say something when you cut to the chase. "I love you as well senpai" you confessed to him. Dazai froze and then happily lifted you up and twirl you around happily like a kid who got his first candy. The both of you laughed at the unexpected confessions. After Dazai stop twirling you around, he puts you back on the ground and pecks your lips making you blush a thousand shades of red. "Looks like my oblivious (y/n)-chan is finally my girlfriend now~❤️" teased Dazai. "S-shut up already!" you yelled while trying to hide your blush.

That is how the both of you ended up dating with each other.

The end

Extended ending

"Seriously kitty? Out of all people that you could date, you really had to choose that maniac? Chuuya complained when he saw the scene between both you and Dazai. Chuuya went out of the cafe since the both of you took too long and didn't expect that to see the newly formed couple. "Welp as her brother I'm just gonna support you (y/n). I'll make sure to beat Dazai's ass if he ever hurts your feelings." said Chuuya as he just smiled at your direction.

Himiko: I can definitely see Chuuya being an older brother you know🤭 Well I didn't expect this one shot to be around 2700 words. The idea just came flowing inside my head so why not go all out? I hope you all enjoy this one shot and until then goodbye 👋

Written on: 17 March 2023