A Cautionary Tale
Ganbari Nyudo is a yokai that watches people using the toilet, especially on New Year’s Eve. He’s not particularly scary, as that’s all he seems to do.
Here’s his origin story as written in 列国怪談聞書帖 by Jippensha Ikku around 1802:
“In Nara Prefecture, a man ensnared in the ways of the flesh (!) was remonstrated for his tendencies by a family member. He shaved his head and went to live as a hermit in a hut in the mountains. He did his utmost to ignore woman and came to be known as “the striving bald one” (ganbaru is a verb meaning to strive, and nyudo is a term for a bald head like a monk–but the commonly used kanji in this yokai’s name are different).
One day, a brigand came to the hut while the man was away. He found a girl who had been kidnapped and shut in by the bald one (I don’t think he completed his 12-step program). The brigand felt pity for the girl, but when he tried to release her, the bald one returned. The brigand killed the bald one and returned the girl to her parents.
After that, the bald one’s ghost began to appear in a white kimono at the girl’s house. The parent’s hid the girl and the bald one began looking for her in other houses, stables, and outhouses around the village and frightened the villagers.
However, one night the bald one was killed by a dog. At daybreak, a dead fox was found in a white kimono. Everyone laughed and said the fox had met an untimely end due to pretending to be the bald one’s ghost (just like a sitcom, it ends with everyone laughing!).”
The above story is an interesting cautionary tale against leches, but other scholars insist Ganbari Nyudo is more closely related to older, less malevolent bathroom kami. And that seems to make more sense given the variety of themes found in his stories.
For example, in his book 甲子夜話 (1821), the author Matsuura Seizan writes that if you chant “Ganbari Nyudo” in the bathroom, his bald head may appear out of the dark toilet. You should take his head and put it in your left sleeve and then take it out again, and it will turn into koban, the oval gold coins used during Edo Era.
Like in the gold coin story, in some times and places it seems Ganbari Nyudo’s presence is desirable, but he’s generally written about as undesirable and methods of getting rid of him are often outlined. The above illustration of Ganbari Nyudo spitting out a cuckoo was made by Toriyama Sekien and published in his book “The Illustrated Night Parade of a Hundred Demons” (今昔画図続百鬼) in 1779 (which, incidentally, you can see most of on the linked Wikipedia site, it’s also worth checking out his other books there).
In Toriyama’s writings, the emphasis is on how to make Ganbari Nyudo go away. He writes, “On New Year’s Eve, if you chant, ‘Ganbari Nyudo, hototogisu (lesser cuckoo)’ the yokai will not be seen.”
There seems to be some confusion about the relationship between Ganbari Nyudo and the cuckoo. The most reasonable argument I read named a kanji error as the source. Toriyama also references a bathroom kami by the name of Kakuto, who brings a mix of misfortune and happiness.
The kanji for Kakuto is 郭登, the kanji for lesser cuckoo is 郭公, and evidently, perhaps to his mind at least, you could invoke Kakuto by mentioning the cuckoo in the bathroom. However, Murakami Kenji points out in his book Yokai Jiten 妖怪辞典 (2000) that Toriyama’s belief that the kanji were the same was an Edo Era misreading.
The phrase “Ganbari Nyudo hototogisu” was also said to bring misfortune if remembered on New Year’s Eve, which was perhaps an older belief stemming from China.
In the Chinese book (荆楚歳時記) written circa 400AD, it says the person who heard the primordial cuckoo’s first cry was split into pieces, or alternatively, the person tried to imitate the cuckoo’s cry and began to vomit blood. Because of that story, hearing the cuckoo’s cry in the bathroom was considered unlucky. To avoid hearing the cuckoo, the book indicates a person should bark like a dog to frighten off nearby birds. However, the dog-barking bit of the story is not well-known in Japan and somehow saying the word ‘cuckoo’ in the bathroom came to be lucky (?)
In conclusion, it’s probably not very good luck to talk about the cuckoo in the bathroom.
If you see a bald yokai peeping in the window, I suggest you teach him a lesson about what happens to peepers. You could try sticking his head in your sleeve, but I fear that would only encourage further bad behavior.