You’re Makomo.

Makomo and Sabito both were dead because of a demon they both couldn’t kill in final selection.

Makomo made Tanjiro smarter and Sabito was the one who fought him to train him to fight.

She were a beautiful yet innocent soul which was cute in Sabito’s eyes but he was dirty minded.

Whenever Makomo had talked to Tanjiro, Sabito would watch from the boulder with jealousy.

Right now he had pinned you against a wall and he was jealous.