Ten days after Aizen's defeat

(Y/N) had just exited the Senkaimon, stepping foot into Soul Society with Calavera in his arms. Next to him was Urahara, Wiz and Rukia.

Wiz: So this is Soul Society, huh? Never thought I'd see it...

(Y/N): I can understand why. Arrancars for the longest time have been enemies with the Shinigamis.

Wiz: Being allowed in willingly feels strange if I'm being honest.

Rukia: Nobody can fault you for that.

Urahara: Besides the aftermath of the war, this'll be my first time returning to Soul Society since my banishment.

Calavera: And this is my first time returning to the Soul Society since I was thrown away.

(Y/N): This is starting to sound pretty depressing.

(Y/N) thought back on how he even got in this situation to begin with.

(Flashback) The day before entering Soul Society.

School had just ended and (Y/N) was walking home with Keigo and Mizuiro. (Y/N) then got a call from Urahara. (Y/N) answered his phone.

(Y/N): Hello?

Urahara: Yo, (Y/N)! How's it going?

(Y/N): Good I guess... Is something wrong?

Urahara: If it isn't much of a hassle, do you think you can stop by the shop?

(Y/N): Sure. What's the situation?

Urahara: It seems I was right about Soul Society summoning you on the day of the trial. Rukia's here at the shop. She'll be our escort there.

(Y/N): She is? Then I shouldn't keep you guys waiting.

Urahara: We'll see you there.

*Click*

Keigo was the first one to speak up.

Keigo: So what's that all about?

(Y/N): Shinigami business. Sorry but I gotta split here.

Mizuiro: Are you going to be okay?

(Y/N): Yeah, I'm not doing any fighting, so don't worry.

Keigo: Well in that case, good luck.

(Y/N): Thanks.

(Flashback End)

(Y/N) decided he would bring along Wiz, as he believed that she would be of help in the favor he wanted to ask for. (Y/N) wasn't sure if bringing Urahara and Wiz was allowed but he at the very least felt like they'd make an exception this once.

The group entered the Head Captain's Quarters. The moment they entered, They saw two familiar faces sitting down with the Head Captain and his lieutenant.

(Y/N): Huh? Harribel? Nel?

Harribel: Good to see you again, (Y/N).

Nelliel, who was still in her adult (Original) form, was ecstatic to see (Y/N).

Nelliel: (Y/N)!!! You remember me right! I know I look different but it's me! Nel!

(Y/N): *chuckle* Of course I do.

Harribel had to calm Nel down.

Harribel: Please Nel, we're in the middle of a meeting. We have to act more professional than that.

Yamamoto: It's quite alright. (Y/N) (L/N). I see you've brought guests with you. One, I know all too well. Please, sit. Ms. Kuchiki, you may leave.

Rukia: Sir.

Rukia gave (Y/N) a thumbs up before leaving.

(Y/N) and the other sat next to Harribel and Nel.

Yamamoto: I apologize for calling you here on short notice, but I assume you have a grasp on what this conversation is going to be about.

(Y/N): Harribel being here means there's some sort of peace treaty being created, am I right?

Yamamoto: Indeed. And it's because of you that this is even possible, so I'm here to ask you of a favor.

Urahara: *thinking* Here it comes.

Yamamoto: I hate to ask this from a human after everything you've done for us, but you're the only one we can ask. Will you become the Shinigami's representative ambassador to this treaty?

Everyone in the room besides Urahara was taken aback.

(Y/N): An ambassador? So you want me to be the diplomat between the Soul Society and Hueco Mundo, keeping a healthy relationship between the two, correct?

Yamamoto: Yes, that's correct. We were just discussing who should be the representative from Hueco Mundo.

Harribel: I originally brought Nelliel here to be the representative, but seeing as Waleska is now present, may I ask-

Wiz: No need. I'll accept.

Harribel: R-really. I thought you would want to stay with (Y/N)-

Wiz: I could always visit him whenever. And if (Y/N)'s the representative for the Soul Society then there's no reason why I wouldn't be in contact with him.

(Y/N): You've thought of all that, that quickly?

Wiz: Mhm.

(Y/N): This is a lot to take in... I still have a lot of responsibilities as a highschool student. And that'll only increase as I get older. Can I really juggle all of that?

Yamamoto: Don't misunderstand. We're not asking you to this forever. We only ask that you bare with us until we can work out a way of proper communication and camaraderie. At the end of the day, you're not a shinigami of the Court Guard Squad. We don't give you orders on how you proceed with maintaining a relationship with the arrancars in Hueco Mundo.

(Y/N) thought about it for a bit. (Y/N) could still live his life as a highschool student and visit Hueco Mundo whenever he wasn't busy. Yamamoto isn't really putting a gun to his head to go back and forth and report every single detail of the arrancars to him.

(Y/N): Hm... Alright then. I'll do it.

Yamamoto: We're glad to hear it.

Yamamoto and Harribel continued to iron out the details between the peace treaty. As the meeting came to a close, (Y/N) decided to speak up.

(Y/N): Um... Head Captain, May I ask for a favor.

Yamamoto: A favor you say? What is it?

(Y/N) brought out Calavera and sat her down.

(Y/N): I have a Mod soul in my possession. I know you stopped production of them in exchange for the Gikon, but so far my Mod Soul has proven to be a valuable person to me. So I wanted to ask for Gigai specifically for her.

If Calavera had eyes, they'd be widened in shock.

Calavera: H-Hey (Y/N), you don't really think-

Yamamoto took a look at Calavera and then at Urahara.

Yamamoto: I see... so that's why you brought Urahara with you.

(Y/N): Yes sir. I've also been told that Captain Kurostuchi's lieutenant was a result of combining both a Gigai and a Gikon. I was wondering if the same can be done for my Mod Soul.

Yamamoto stood quietly for a second before he spoke.

Yamamoto: I'll get in contact with Captain Kurostuchi and inform him that you'll be stopping by.

Calavera was at a loss for words.

Calavera was honestly surprised (Y/N) remembered their promise. She honestly didn't mind living in her stuffed animal body anymore. She was around people who genuinely wanted her around. (Y/N). (S/N). The Urahara shop staff. And now (Y/N)'s friends were aware of her existence.

If the stuffed body Calavera was currently in had the ability to cry, she'd be doing it right now.

(Y/N): Thank you so much!

Yamamoto: Do not thank me. This is a result of your hard work in the war. You've helped us fix a problem that we caused that could've plunged all three realms in chaos. This doesn't even measure up to what you and Ichigo Kurosaki have done to help us.

So that's what this is about. If that's the case. Then maybe when Ichigo wakes up, he could potentially ask them to return his powers of a Shinigami.

Yamamoto: Now then. I believe that's the end of our meeting.

Everyone was dismissed. As the group exited the Head Captain's quarters, Harribel spoke up.

Harribel: Now then, I guess we'll be going. Waleska-

Wiz: Just "Wiz" is fine.

Harribel: Alright then. Wiz, will you be joining us?

Wiz: I'll be staying here a bit.

Nelliel: In the Soul Society?

Wiz: Yes. (Y/N) informed me last night about his plan to provide Calavera here with a body. With me, Kisuke and that grumpy old scientist, we'll be creating a perfect Gigai suitable for our little bunny rabbit.

Harribel: I see. Then we'll be awaiting your arrival at Las Noches.

(Y/N): Do you guys have an escort?

???: Yeah, and it's us.

(Y/N) turned around and saw-

(Y/N): Renji? and Hanataro? We haven't seen each other since the Soul Society invasion.

Hanataro just scratched the back of his head shyly.

Hanataro: Well... I was in Hueco Mundo, and I ran into Rukia there. Unfortunately we didn't run into each other...

(Y/N): Really? Well I'm glad you were there to help regardless. Well I shouldn't hold you guys up.

Renji: If you're here when I get back, we should hang out (Y/N).

(Y/N): Of course.

Nelliel: So you later (Y/N).

Harribel: Farewell, (Y/N). Let's go Nelliel. With Grimmjow still alive I'm scared he'll mess the place up. Starrk may be too lazy to do anything about it.

Nelliel: Of course.

Harribel and Nel left with Renji and Hanataro.

...

...

...

(Y/N): Wait a minute, Grimmjow's still alive?

To be continued.

Remember all the way back during Calavera's introduction when (Y/N) promised to get her her own body? It finally came full circle.

Also considering the arrancars and shinigami didn't have any issues after the fight with Aizen, it's pretty obvious they'd do their best to maintain the peace.

Yamamoto only asks that (Y/N) assist for the beginning stages as he seemed to be the most friendly with them. Being an ambassador of sorts means that can visit the Soul Society with pretty much no strings attached.