It was a lonely night at the Butterfly Mansion where Tanjiro was. Well, it was only lonely because most of his companions were asleep.
He himself couldn't sleep, though. It wasn't abnormal for him, after all, seeing the corpses of your family after being murdered by a Micheal Jackson look-a-like, whoever that is, does not make for a healthy psyche.
On sleepless nights like this, Tanjiro would do some exercises or extra training. There were also times when he would do what he's doing now, taking a walk outside.
It wouldn't be something he'd be doing if he thought there was danger. After all, he wasn't currently on a mission, and a demon not named Nezuko wasn't nearby as far as he knew. It was a perfect time for a nice long stroll under the moonlight.
Tanjiro let the cool, crisp night air enter his nostrils, before circling the manor. As he did, he happened upon the smell of flowers. He followed that smell towards a small pool of water.
Tanjiro's eyes had gotten used to the darkness, enough to see a figure in the water. His breath hitched in his throat. The last time he saw a figure in a pool of water, he had to pull Zenitsu away from it before he got eaten.
But this figure didn't smell like a demon. Tanjiro's eyes followed the figure up and down, noticing it looked very feminine... and very naked...
Tanjiro's eyes widened a little, a blush coming to his face. If this woman was one of the manor's inhabitants, he was in trouble. His eyes traced the figure, brain still registering it when the figure slowly turned her head.
Tanjiro immediately turned and sped off.
Tanjiro lay in his bed, holding the covers close to his chin. Oh no, running away probably made me look worse. Okay, think of a plan. Well, I could always blame Zenitsu, say that he put me up to that. No one would believe him, and it would be funny... no, that's too mean... Tanjiro shook his head with a sigh, I'll be honest and say that it was a complete accident, she'll believe me, right?
Then he turned his head, noticing Kanao staring at him. He was about to say something before she put a finger to his lips with an "Shh, you'll wake them up." She whispered.
Tanjiro stared at her for a brief second.
"... What you saw, did you like it?" Kanao asked, leaning into his face.
Tanjiro's own face burned, before he quickly whispered, "I'm sorry, I-I didn't know it was-"
Kanao shushed him again, "I know. I know you wouldn't do anything horrible. Next time, though... because it's you, I might let you join me."
Tanjiro's eyes widened at this.
In the bed next to him, Zenitsu lay awake, staring at the wall in anger, "That lucky son of a-"