After the swordsmiths villiage many slayers were Assigned a hashira to train under.

While looking for the Hashiras you stopped and wondered "Hey wait! Why isn't giyuu in the assigned Hashiras?!"

So you went off to Tomiokas estate to see why. And when you arrive you see Tanjiro screaming in giyuu's face while giyuu looks on in a deadpan stare.

"GIYUU-SAN❤️" Tanjiro shouts excitedly.