It’s the lead up to a huge conflict, but why did Daki throw a tantrum?
Daki decides to throw a tantrum because Tengen doesn’t believe she’s an Upper-Rank Demon. The Hashira is dismissive of Daki’s claim that she’s powerful, as he easily decapitates her.
This tantrum unleashes Gyutaro, Daki’s brother and the more powerful side of Upper-Rank 6.
Daki decides to throw a tantrum
In chapter #85, Tengen, the Sound Hashira, easily decapitates Daki. Tanjiro is shocked that an Upper Rank demon could be disposed of so easily, but he still has Nezuko to worry about.
Previously, Nezuko assumes a new form that’s more suited to fight against an Upper-Rank demon. Still in this form, she fights and resists her own brother who tries in vain to calm her.
Tengen begins to lose his patience. He urges Tanjiro to sing his sister a lullaby in order to subdue her. Tanjiro does sing a song, calling back to a tune that Nezuko’s mother used to sing. This song successfully takes Nezuko out of her demon-filled trance and puts her to sleep.
Once Nezuko calms herself, Daki shouts out to Tengen. The Hashira begins walking away, but Daki blurts out that he’ll never get away with cutting off her head.
Tengen says that Daki bores her. Embarrassed, the demon asks why the Hashira says she’s not an Upper Ranker.
Due to her defeat coming so easily, Tengen says she can not possibly be an Upper Rank demon. Daki refutes this, declaring she is Upper Rank 6. She asserts that she’s never lost in battle and has rightfully earned her spot.
Completely dismissive, Tengen says he’s not convinced. This enrages Daki further, who bursts out into tears.
“It’s true,” Daki screams out. “I really am Upper-Rank 6! I have a number on my eye and everything! Because I’m so amazing!”
After pounding on the ground and making more of a scene, she calls out her brother. Gyutaro, the other half of Upper-Rank 6, unleashes himself from within Daki’s body.
Gyutaro is a force to be reckoned with, easily attacking the Demon Slayers and even breaking Tanjiro’s fingers.
So that’s the answer. Daki decides to throw a tantrum because Tengen doesn’t believe she’s actually an Upper Rank demon.