as Tanjiro, Inosuke, and Zenitsu were heading toward the Wisteria family since night was falling they heard and saw you fall from the sky

Tanjiro: "What is that?!" Inosuke: "MY KILL!!!" Zenitsu: "IS IT A DEMON?!"

they saw you unconscious and took you with them to the Wisteria family, then an old woman sees them all and lets them come in and stay for being demon hunters, which in the past some of them saved her life and is now thankful for them.