pillars of the future (young geek cosplay)

It was the Taisho era. The Hashira were eating at a restaurant that served traditional food; all the Hashira were there along with Tanjiro, who was Tokito's only friend. They were chatting normally when they saw Tokito with a phone while he ate, and they asked him where he got it from.

Rengoku: Young Tokito, where did you get that cell phone?

Mitsuri: It's bad manners to do that, Tokito she said while eating 20 bowls

Tokito: I don't remember he looked at Mitsuri, somewhat bored, until you appeared (you were his only best friend). He stood up and hugged you
The Hashira were surprised because they didn't know Tokito had another friend besides Tanjiro. They were about to ask Tanjiro until they felt the floor open up and suddenly they were transported to the modern era. They appeared in modern clothes and without katanas, only cell phones, until the Master appeared as a hologram to explain that their mission is to defeat Muzan, who in this digital era uses cell phones to control people