Tanjiro froze where he stood, his nose twitching sharply.
As someone with an extraordinarily keen sense of smell, he could distinguish the faintest scents of emotion in the air in an instant.
At that moment, the scent coming from Nezuko no longer carried the coldness and frenzy of a demon that it once had.
He smelled sorrow. It was the sorrow of sharing her brother's pain after hearing his anguished confession.
He smelled reluctance to part. It was an overwhelming reluctance born of fearing that her brother would face danger alone, of fearing the loss of family.
More importantly, amid that intense sorrow and reluctance, he smelled an extraordinarily powerful resolve!
It was the determination to stand beside her brother, to face every danger together, to slay those demons together!
"No! Nezuko, listen to me!" Tanjiro instantly understood what his sister meant. He abruptly crouched down and gripped Nezuko's shoulders tightly with both hands, his voice growing urgent and stern. "You can't go! The world outside is too dangerous! Those demons are incredibly powerful, and... and Muzan already has his sights on us! You're a demon now. Once you go outside, if you encounter sunlight, if you run into other powerful demons... you'll die!"
Tanjiro's eyes were filled with fear. He could not imagine how he would go on living if Nezuko were hurt. He would rather his sister lie safely within this barrier for the rest of her life than have her set foot on that bloody battlefield.
"Be good and let go. Your big brother can manage on his own. Mr. Rokuya will help me, and the Master will protect you too. Just sleep here and wait for me to come back, all right?" Tanjiro tried to pry Nezuko's hands loose.
But Nezuko's hands seemed cast from iron.