Besides, he should have minded his own business, that sensei.
Okita was used to all types of injury, injuries worse than the small bruise on his arm. His former sensei pushed him to the point of near death just to improve his skills, and Okita loved that sort of training. Ignoring the self to gain self improvement, that was real kendo for Okita, not this half baked kendo club he was in at the moment.
Those people seemed te be in that club, just for the fame, or just for the heck of it, not really respecting the art of kendo, and Okita hated it. He even felt insulted to call those people his superiors. The didn't deserve his respect.
And yes, that sensei didn't mind his own business.
One senior member, obviously didn't know anything about caring for his shinai. A minute of sparring with Okita and small pieces of sharp bamboo bits flew off his sword. And if Okita hadn't been quick enough to shield his eyes with his arm, he would have had an eye injury.
Normally, this was nothing and Okita could continue sparring in top condition. But the sensei stuck his nose in and forced Okita to stop his club activities and go to the clinic even though he didn't want to, telling him that he would not be allowed to attend club activities without going to the clinic.
And this really pissed Okita off, although he didn't show it.
Fifteen minutes had passed, and here he was, standing in front of the school clinic.
Better get this over with and go home...hope the doctor isn't as annoying as that fake sensei...