Short Short: Kofun Syndrome

"Kofun-kofun."
My classmate Sakai makes a strange coughing sound in the school cafeteria. Is it hay fever, or maybe a cold? Before I can ask, Sakai cuts me off and says,
"'Kofun syndrome.' I've been doing too much fieldwork."
Kofun syndrome? I've never heard of such a disease. It's true that Sakai is in the archaeology department and talks about nothing but burial mounds, but still.
"Did you inhale some bad dust from a ruin? Like the curse of Tutankhamun?"
He chuckles and coughs lightly. He says it with a look of genuine happiness.
"I don't mind a curse. I love them, after all. I guess I just pushed myself too hard and got my fill, but I'll get used to it soon."
What an idiot. I'm too stunned to even speak. What's so fun about staring at earthenware and haniwa all day? I tell him to "take it easy" before we part ways, and I check the time on my phone. I have volunteer work this afternoon: organizing the catalog at the university library. I'm scanning through a collection of books recently donated by a local notable. They were beautiful books. There were even manuscripts. My mouth curls into a smile at the sight of the pile of old books. Suddenly, I start to cough.
"Kohon-kohon."

Short Short No. 790

I am participating in Nika Tahara's "Weekly Short Short Note."
This week's theme is "Kofun Syndrome."