Obanai was mid-way of cutting his long black hair to stop remembering his past. But, yet he was also getting a coronation for becoming a hashira..

...Obanai just started cutting his hair due to it just the being of his mental breakdown. He was upset and annoyed that his hair wasn't going up so he chopped some of it off as a solution. Then that when he saw you, his mother..

a hallucination of his own mother.. as his face frowns.. what in the world were you doing here.