Web-fingered kappa, long-nosed tengu and oni demons ... During the Heian period (794-1192) through to the Edo period (1603-1867), traditional folklore spirits and monsters known as yokai often became subjects of picture scrolls and ukiyo-e prints. But after the Meiji era (1868-1912), yokai quietly faded from the spotlight. Where did they go?
Yokai researcher Koichi Yumoto started digging for answers, and came across yokai at last - in a newspaper in the Taisho era (1912-1926).
A local newspaper reported in May 1913 that a 14-year-old girl had been thrown into a river by a big man in Yamanashi Prefecture.
The article said, "Neighbors are terrified it might be the work of a tengu."
Yumoto also discovered articles reporting bizarre events one after another, such as "a tree making a strange voice" and "the capture of a mermaid."
"At the time, people apparently still believed that inexplicable phenomena were the work of yokai," mused Yumoto, 64, who published a book in June compiling such yokai-related articles.
About 30 years ago, when he was a researcher on the history of currencies, he became preoccupied with yokai research after finding a sugoroku board game featuring yokai created in the Edo period at a secondhand bookshop.
"I figured people in the old days had just been scared of yokai. But I was surprised to learn they were also amused by them," Yumoto said.
He worked for the Kawasaki City Museum for many years, where he organised an exhibition featuring yokai that was extremely popular. Yumoto currently teaches at Hosei University Graduate School.
"Studying yokai is like studying the minds of people. Yokai are endlessly interesting to me," Yumoto said.