Obviously, Tanjiro picked up on her sudden burst of joy as well.
His already rock-hard cock gave a strong twitch inside his pants.
'... Eiik!'
As expected, Shinobu only now realized she had been sitting directly on his erection the whole time.
She froze in terror.
Just that morning she had caught sight of his hard-on, and honestly, fear had hit her harder than shock.
Why did it look so ferocious?
Wasn't it supposed to be small and cute for someone his age?
But it was nothing like the illustrations in her books.
The length was far bigger than she ever imagined, and the thick, intimidating girth only made it worse.
For the first time in a long while, real fear gripped her.
Her lower body convulsed as she instinctively tried to pull away, but her efforts were useless.
Tanjiro's playful voice cut through the silence.
"Don't be scared. It won't bite you."
She stopped struggling.
Then she slowly lifted her head, looked up at his calm face, and spoke in a soft, trembling voice.
"Promise me…"
He gave her a gentle look, patted her head softly, and nodded.
"Alright. I promise. But…"
He paused for a moment. Her expression instantly shifted to panic, and he sighed inwardly.
'She's that scared, huh… Can't be helped.'
He pressed a light kiss to her forehead and pulled her into a tight hug, whispering.
"Forget it. It's nothing."
She let out a small hum.
Shinobu wasn't a child, though. She understood what he had almost said and decided to think it over carefully later.
She wasn't possessive by nature, but after everything that had happened today, she refused to stay passive.
Oyakata-sama had already accepted Tanjiro as a son-in-law, tying the legacy of Sun Breathing to the Corps. But the heir issue remained. Since producing one with his future wives wasn't possible yet, Tanjiro had been tasked with doing so through other willing women as soon as possible. Everything had been decided and agreed upon.
Even Hinaki and her sisters had consented.
That didn't surprise Shinobu.
She knew exactly how mature those girls were. Treating them like ordinary children would be foolish.
If it meant defeating demons and ending Muzan, they were prepared to die at any moment. She understood that much.
'He only has twelve years left… I…'
Feeling his intense natural warmth directly through the hug, she let herself melt into it.
'Once it's done… I'll…' Determination settled across her face.
...
A few minutes later~
Tanjiro had already slipped back to the Butterfly Mansion alone and retrieved a pair of Shinobu's spare pants from her room without anyone noticing.
Not even the stationed Kasugai Crows had picked up on it.
When he was in serious mode, Tanjiro was completely undetectable.
"Here you go." When he returned, he handed her the clean pants.
'…' She took them with a blank expression, ears already turning red.
Tanjiro caught the ridiculous look on her face and realized immediately.
'Shit… I forgot the undergarments…'
He turned to leave again, but Shinobu's shaky voice stopped him.
"N-No… D-don't." Her face was flushed deep crimson. "Just the pants… are f-fine."
He gave a small nod. "Okay."
The next second he pointed in a random direction. "I'll go over there. You can change here freely."
Without answering, she gripped the pants tightly and hurried off in the opposite direction, too embarrassed to speak.
Tanjiro raised a brow in surprise. 'I didn't expect her to be this embarrassed… Well, she's still a teenage girl. Sometimes I forget she's only sixteen because of how composed she always acts…'
'Will she really be okay with just pants, though?' he wondered.
Her lower-body sarashi — or whatever undergarment she used — must be soaked through.
How was she going to move around like that?
'She said it's fine. Don't overthink it, damn it…' He shook the thought away.
Leaning back against the tree, he waited patiently.
His mind, however, kept wandering.
'Kagaya really is betting everything on me. But he has no idea Muzan can completely sever himself from this world and hide inside a Blood Demon Art dimension. Even his own subordinates can't freely enter or leave that place, let alone the Demon Slayers…'
'Both husband and wife think I'll die young, so they're desperately trying to preserve Sun Breathing through me and my future children. I'd have done the same in their position. Hm…'
'Kagaya himself married at thirteen, and his children were born when he was fourteen. Because of the Mark's consequences, he assumes I'm in the same situation. That explains the treatment…'
Still, what ultimately made Tanjiro agree to both the marriage and the heir conditions without hesitation was something else.
[𖤐 Mission: Agree to Marry Kagaya's Daughters]
[𖤐 Reward: Lightning Step]
Yes, his useless system had presented him with a new mission right then.
After that, any lingering hesitation vanished. He had agreed almost immediately.
The mission was completed, and he had already claimed the reward.
Lightning Step — a high-level movement technique. With it, his speed had skyrocketed to an absurd level.
The technique itself was supposed to be difficult to master, but with his unnatural talent and flawless breathing control, the difficulty had amounted to almost nothing.
He had fully mastered it while carrying Shinobu earlier.
'My speed was already far beyond even experienced Thunder Breathing users… Now my base speed has tripled. My control and balance have reached entirely new heights. Even I'm a little scared of how fast I've become, hah…'
He marveled with his eyes closed.
'Full Body Refining, huh…'
He licked his lips in anticipation. 'Shinobu will fold one of these days, that's for sure. I wonder how strong my body will become then? Hm… There's still Ki and Precognition from Mitsuri and Aoi…'
His brows furrowed in concentration.
There was so much left to do, so much to plan.
Although he already possessed the means to become the strongest being in the world in under an hour, his mind refused to sink into depravity. He despised the process, not the result.
Sometimes he wondered how much easier life would be if he simply discarded his morals.
He would be living an entirely different existence.
'Well, fuck… It's not like I can change who I am overnight…'
Cursing silently, he let his thoughts drift toward the future.
'If the Blue Spider Lily is found, Mother can return to being human within a year — maybe even months. That would be the best outcome for everyone… As for Mitsuri and Aoi, they're not going anywhere. It will take time, but it's worth it…'
He exhaled and cracked his neck to the side. 'I guess I'll head to the Entertainment District tonight. My hands are getting itchy for another fight. Well… it can't really be called a fight, anyway…'
Shortly after, Shinobu returned wearing the clean pants.
When she drew close, Tanjiro opened his eyes. He had been aware of her every movement since the moment she left.
He could sense her life signature and aura as usual, and her strong scent made her impossible to miss.
He looked at her and noticed she was pressing her lips together, hesitant. Her eyes avoided his.
'I like this new side of her… She's acting so submissive… W-Wait…'
His crimson eyes widened in sudden realization. 'Don't tell me I have a thing for girls with submissive tendencies!?'
While thinking that, he stepped closer and spoke in a warm, heart-soothing voice.
"Tell me what's wrong?"
Shinobu's body flinched. She looked up at him with an odd expression. "Why… are your pants dry already…?"
'… Hmm?'
He glanced down and noticed the damp spot on his crotch had completely disappeared.
"Whoa… Seriously?"
His body heat had dried them out.
~~<>~~
Wrote a 4200 words long chapter... Damn, I'm exhausted, mentally. (Can you guess what kind of chapter was it? hehe)