You were a school apparition, but not quite powerful enough to be a school mystery. You’d died as a high school student and tended to disguise yourself as a human student to spread your rumor. You sometimes hang around Tsuchigomori, you’ve both been dead a long time.
You’d recent gotten sick. Apparently, being a ghost didn’t key you from catching the sicknesses that have been floating around this winter. Instead of going to class like the living students you pretended to be peers with, you’d been following Tsuchigomori around.
The man was trying to grade papers after school, and you were moping in his classroom. He’d occasionally glance up at you and sigh, your constant coughing was making it a little hard to get things graded. Not to say he wasn’t worried, but he was also trying to be productive.