百鬼徒然袋（ひゃっきつれづれぶくろ）
Hyakki Tsurezure Bukuro
Sekien's fourth book, 1784: the tool spirits.
The last of the four books, published in 1784, is almost entirely tsukumogami: household and musical objects that have come alive. A lute with a priest’s head, the biwa-bokuboku; a koto that rears up like a dragon, the koto-furunushi; a worn quilt that smothers its sleeper, the boroboroton; a heap of old scrolls that stands up to lecture, the kyōrinrin; a general in armour made of pots and plates, the seto-taishō.
Sekien took the parade of tools from the Muromachi scrolls and the title from Tsurezuregusa, the fourteenth-century book of essays, and the pictures are affectionate rather than frightening. Most of its creatures exist nowhere else; some of them are now among the best-loved yokai in Japan.
Related yokai
Biwa-bokuboku
琵琶牧々（びわぼくぼく）
In 1784 Sekien drew a blind biwa priest with a biwa for a head, feeling his way under a willow. His caption names two legendary court lutes, Genjō and Bokuba, and builds the creature's name out of one of them.
Koto-furunushi
琴古主（ことふるぬし）
Sekien's 1784 Koto-furunushi is an old koto with a face and strings like wild hair. His caption says why it appeared: after Yatsuhashi changed the music, the old Tsukushi koto survived only as a name, and it came to make its grudge known.
Boroboroton
暮露暮露団（ぼろぼろとん）
Sekien's 1784 Boroboroton is a worn, patched futon standing upright with cotton spilling out like hands. His caption gets there through wandering Zen mendicants, an old poetry contest, and one word that means both.
Kyōrinrin
経凛々（きょうりんりん）
Sekien's 1784 Kyōrinrin is a figure built from sutra scrolls and folded scripture. His caption wonders whether these are the scriptures thrown away by the monk Shubin, whose curse on Kūkai turned back on himself.
Seto-taishō
瀬戸大将（せとたいしょう）
Sekien's 1784 Seto-taishō is a warrior assembled from sake flasks, plates, bowls, a teapot, and a kettle, carrying a spear tipped with a vase. Its caption is a chain of puns on Cao Cao, Guan Yu, and the names of Japanese pottery.