[Demon Slayer] What Do I Do When I Suddenly Have a Little Brother?

While recovering at the Butterfly Mansion, Zenitsu Agatsuma suddenly acquired a younger brother, without even realizing it himself.

The person in question expressed his anger and condemnation: "Huh? Who? I don't have a younger brother! Don't go assigning relatives to people, okay? That's really out of line! Liars should swallow a thousand needles. Who's spreading these ridiculous rumors?!!"

"Huh? But everyone in the Demon Slayer Corps says so."

Tanjiro looked uncertain.

"He came to help out at the Butterfly Mansion before, and I saw him too. He really does look a lot like Zenitsu: the color of his hair, his eyes, even his voice..."

"Excuse me..."

A voice so familiar it made his scalp tingle suddenly sounded outside the door, cutting off Tanjiro mid-sentence.

"..."

It was a voice he heard every day, one that came from his throat when he cried, screamed, or threw a tantrum. It was unmistakably his own voice, yet it rang out somewhere else while his vocal cords hadn't moved at all.

Zenitsu Agatsuma jolted and whipped his head toward the door.

Golden hair, golden eyes, seemingly a little younger than him. The contours of his face held a faint resemblance, though Zenitsu was loath to admit it, and the boy was definitely a little cuter than he was.

"Aoi is busy with other things, so I'm delivering today's medicine. Three servings."

The blond boy held up a tray with three cups of herbal medicine and met Zenitsu Agatsuma's gaze, the latter frozen in his sickbed, while wearing a confident smile.

"Tanjiro's serving, Inosuke's serving, and..."

His unusually colored golden eyes gleamed with interest.

"...Zenitsu Agatsuma's, right?"

1. Nohara Maru is a character from Kemono Jihen. He usually appears as a golden-haired little boy, but also has a handsome adult form. He shares a voice actor with Zenitsu Agatsuma: Hiro Shimono.

2. Nohara Maru has crossed over into Demon Slayer.

3. Nohara Maru is Neutral Evil.

4. Voice actor joke.

5. Title undecided.

Theme: Though they have no blood relation, everyone mistakes them for brothers.