Once you finished Mitsuri's training, you went out to go to where the snake hashira Iguro Obanai's training was, but he had a huge grudge against you. because he was jealous that Mitsuri had so much fun with you, so Iguro despises you.

Obanai: A... So you are coming to train? You had fun with Mitsuri, didn't you? Then I'll make that smile disappear completely.

Both entered a place where several low-rank demon slayers were tied up in different directions.

Obanai: your goal will be to hit the small spaces without hitting the demon slayers, but if they do hit them, anyways no one cares, they should suffer in silence.