Demon Slayer’s Sentinel Sanitarium (A Free Bonus Story)

*Still mainly focused on the Tsugikuni brothers, with most characters portrayed as villains. The full story is free. Please scroll down to read the content warnings first.

Welcome to the Demon Slayer Sentinel Recovery Center! Our patients include an utterly brainwashed cult leader who started working at the age of three, a tattooed fighting king with severe amnesia, and an unstable person with a stimulating gender transformation...

But there's no need to worry about our patients' health. We have top-tier Alpha Guides, advanced treatment methods, and excellent inpatient facilities. The Central Tower and the Ubuyashiki and Kibutsuji conglomerates have invested heavily. You deserve this! Yes, you, the head of the Tsugikuni family!

Michikatsu: ...

Michikatsu: I didn't... check myself in... voluntarily...

*

During a mission, Tsugikuni Michikatsu realized something was wrong with his spirit animal. The cat that usually curled up obediently on the beach had vanished without cause. The pent-up pressure in his mental landscape erupted into a storm in an instant, dealing a devastating blow to the sentinel. Blood flowed from his orifices, and his five senses began to fail.

Michikatsu stared at the blood covering his hands, bewildered. What was happening? How could his spirit animal disappear?

Enemy: Incredible! I took down Upper Moon One with a single move and made him spit blood!

Without hesitation, Michikatsu swiftly took care of his opponent and called for help. In the end, he was rushed straight to the emergency room.

Not long afterward, Michikatsu was admitted to the Tokyo Central Tower Sentinel Recovery Center after losing his spirit animal. He was alone, missing his senses, and in a miserable predicament.

Fortunately, Guide doctors and volunteers surrounded him. They had distinctive personalities, but were all serious and responsible. Their names were Gyomei, the Shinazugawa brothers, and the Tokito brothers.

Michikatsu: I have a bad feeling about this...

The same day Tsugikuni Michikatsu's spirit animal disappeared, another Tsugikuni was out and about in the Central Tower residential district. The black panther walking beside him sneezed after getting a noseful of pollen and vanished on the spot.

Yoriichi had no idea when it had become allergic to pollen. No, wait! His mental landscape was empty. Had his spirit animal disappeared?

Because of a pollen allergy???

The dangerous individual Yoriichi was forcibly taken to the hospital in the city center.

*

The head of the Tsugikuni family, still unable to see, made the acquaintance of a strange fellow patient at the recovery center.

The other person never spoke. Sometimes they would casually sit on the floor beside his chair. He would catch a faint scent as they came closer, then feel a flower placed in his palm.

Michikatsu felt along the stem, counting its tiny petals, and made no effort to speak to his fellow patient either. The volunteer Kamado had once stammered that this patient was both deaf and mute, and asked him not to hold it against them.

He said he wouldn't.

If anything, the ones most likely to soften Michikatsu's heart in this world... were deaf and mute children.

Content warnings:

* Mainly about the Tsugikuni brothers' family bond.

* A free bonus story set in one parallel world in the second loop. It can be read on its own; you don't need to read the previous story! Don't read it! Just treat the disappearance of the spirit animals as the work of some invisible superpowered hand. It has no effect whatsoever on the plot of this world.

* Modern Demon Slayer with an ensemble cast, many author-created details, and no guarantee about how many characters will appear. Updates and reading at leisure... A Tsugikuni brothers fanfic with low moral standards (highlight: some scenes contain, in a certain sense, hints of cover-ups and complicity. If you have moral expectations of these two, this book isn't recommended. OOC comedy). Includes dark humor. If it makes you uncomfortable, close the page immediately. Lots of author-created Sentinel-Guide setting details. The big and little cats were introduced in the first place because I wanted to write this. Highlighted warnings: mentions of Obanai and Mitsuri, the Serpent and Love Hashira, as well as a small amount of unrequited, unknowing Giyu and Shinobu. Not a happy ending, not a pairing in the strict sense, but it's a kind of human affection, I suppose. Listing all the warnings in advance for anyone who wants to avoid them.

Theme: Get along well with friends and family