A crackdown on various forms of popular culture accompanying the Tenpo Reforms effectively silenced some writers and publishers, especially that produced koshokugabon (book of pornography), and served as an admonishment to others, such as an accusation against Sunshui TAMENAGA; as a result, ninjobon lost its vigor and creative force, and gokan (literally, bound-together volumes of illustrated books) appeared in numbers larger, to make up for that decline of ninjobon.
天保の改革によって特に好色画本が禁圧され、為永春水らが罪に問われるなど戯作者・版元に圧力が加えられると、人情本は衰退し、その穴を埋めるように合巻の刊行点数が増大した。