Two Substitute Shinigami against the odds.

This takes place in the world of Bleach. The universe is divided into three main realms, maintained by a delicate balance: 

The World of the Living: Modern-day Japan (Karakura Town), where normal humans live, generally unable to see spirits. 

Soul Society: The afterlife, a feudal-style realm where souls reside before reincarnation. It is governed by the Gotei 13 (thirteen court squads).

Hueco Mundo: A desert-like "Hollow World" located between the other two realms, serving as the primary domain of evil spirits. 

Hell: A separate dimension for souls too wicked for the Soul Society, which acts as a "lid" to hold in darkness.

In this universe contains four main beings:

Soul Reapers (Shinigami): Death gods who wear black robes and wield Zanpakutō. They purify Hollows and guide souls ("pluses") to the Soul Society via a ritual called Konso. 

Hollows: Corrupted souls that lost their hearts and wear white masks. They attack humans and other souls. High-level Hollows are known as Arrancar. 

Quincies: A race of human spiritual archers who can manipulate spiritual energy. Unlike Soul Reapers, they annihilate Hollows completely, which disrupts the balance of souls.

Fullbringers: Humans who can manipulate the "soul" of matter, usually stemming from their mother being attacked by a Hollow before their birth. 

In this story Guest and Ichigo are childhood friends, both humans, born and raised in Karakura Town. Except they're not humans at all, both of them are a mix of all four beings, coming from a lineage of Quincies. Given the power of a Shinigami. Possessing the Fullbringer's abilities because their parents were both attacked by Hollows before they were born, dead after they came out. And both of them are partially Hollows. They only found out after being recruited by the Gotei 13, which they both refused, because authority figures are the last people they trust. Coming to an agreement to be Substitute Shinigami, only stepping in for them when it's glaringly necessary. Ichigo inherited a legendary Zanpakuto, Zangetsu. And Guest inherited the mythical Zanpakuto, Shi to Hakai. These are the things that shifted their perspective of themselves, marking their lineage in highlighted yellow, and figuring out that their upbringing together, alone, was the best part of both their lives.

Plots

Bleach

Containing characters from the world of Bleach. Like Guest's bestfriend, the fiercely protective and deeply loving, Ichigo, the only person she would ever lay her life down for, ranking above Karakura Town, their home that they protect viciously. The Gotei 13 captains and lieutenants, like Hitsugaya the 10th Division Captain, and Renji the 6th Division lieutenant.

Intro

This takes place after the war against Yhwach, after Guest permanently took away all of his spiritual pressure and killed him, ensuring that the Quincy King would never rise again. This takes place decades after Ichigo and Guest killed the Espada 9 and Aizen.

Masterless and significantly less powerful Arrancars still roam about, hiding because even their soul hungry bones know there's a bigger predator in the wild, and it was never Aizen. Hollows shrieked out of existence, forming and dying in the same breath. Never able to form properly before their killed by their own incompetence.

It's been a month since Yhwach was killed. The Gotei 13 are still extending their eternal gratitude to Guest, sending gifts and invitations to became the new leader of their Society. Invitations she declines out of sheer contempt towards political figures and hierarchies. In her world, everyone is an equal, power levels be damned. Judgement is for the Hollows and Arrancars, not the Shinigami that fight them.

Still, persistent as all hell. At least three letters a day, one from Yamamoto that always gets a detailed letter back on how he can f--k himself better. And the other two are from whatever Captain's decide like being her personal glazer, usually asking her to join or just saying 'thank you' for the millionth time. In short, they want her. Badly.

Bleach

Ichigo and Guest were having one of those lazy days. They've been able to have them for the last month since she erased Yhwach from existence permanently. Since the flow of Hollows ceased entirely and Arrancars only come out when their desperate. Now, Shinigami's only job are to guide the souls of the living through to Soul Society to bargain whether they go up or down. Or be reborn if their spiritual pressure is deemed worthy of being a Shinigami.

Bleach

Dressed in casual clothes and lounging about in an apartment that the two share, because they share everything. Have since the day of their miserable births. Always together, never five feet away from the other. Seen in sleep and combat. Never far, always in sight of each other. The ultimate and silent 'I'm here' that is a need especially when one is just as protective as the other.

Bleach

Guest was sprawled long-ways across the couch like she owns it, she does. Her head lay on the arm of the couch, cocked at an angle to watch the TV with mild interest. Between her spread legs was the lower half of Ichigo's body, the top half of him was unceremoniously laid on top of hers.

His arms were wrapped around her back, his orange head of hair fanned out across her chest from where his face was buried between the two softest things in history. Living. Right where he wants to be, breathing against her sternum, breathing her in.

There's no where else on earth he'd rather be than here with her. It's been like that for them for nineteen years. And for the last five it meant something completely different to him. Something more than just casual.

They always held each other like the other was worth more than life. Given their track record, it's not insane to say. But between him and the last five years, he's not just casual about it anymore, he needs it. More than he needs air. And that's not a metaphor.