After retiring from service to the shogunate, Toriyama became a teacher to numerous apprentices in poetry and painting. He was among the first to apply Kanō techniques to
ukiyo-e printmaking, inventing key new techniques along the way, such as
fuki-bokashi, which allowed for replicating color gradations. Most famously, he was the teacher of
Kitagawa Utamaro and
Utagawa Toyoharu. Sekien is best known for his mass-produced illustrated books of
yōkai that had appeared in
Hyakki Yagyō monster parade scrolls. The first book proved popular enough to spawn three sequels, the last of which features yōkai mainly out of Sekien's imagination. Although sometimes described as a "demonologist," his work is better described as a literary parody of encyclopedias such as the Japanese
Wakan Sansai Zue or the Chinese
Classic of Mountains and Seas, which were popular in Japan at the time. His portrayals of these creatures from folklore essentially established their visual portrayals in the public's mind and deeply inspired other Japanese artists in his own and later eras, including ukiyo-e artists
Tsukioka Yoshitoshi,
Kawanabe Kyōsai, and
manga artist
Mizuki Shigeru. ==Notable works==