Introduction
When the thermostat drops and the days shorten, what pedestrian could fail to be tempted by the forlorn call of the yaki-imo truck? Hot, creamy, fluffy, and utterly comforting in the cold, roasted sweet potatoes have been one of Japan’s most beloved treats since vendors began selling them from the streets in 1793. You could say that they evoke all sorts of imo-tions.
For many people, satsuma-imo are inextricably associated with autumn — not only the tuber itself, but also the limited-edition sweet potato-flavoured snacks and dishes of all kinds that begin to appear in shops and restaurants every year around September. Think soft serve ice cream infused with the rich golden flesh of Naruto Kintoki sweet potatoes; a mountain of shaved ice layered with honeyed Anno-imo cream; a sweet potato riff on Mont Blanc, with imo puree standing in for the usual chestnut.
Sweet potatoes were first introduced to Japan in the early 17th century. The nutritious, delicious tuber seemed like a miracle food to many. Since sweet potatoes are relatively easy to cultivate and grow, even in low-quality soil, they proved indispensable as a food source during periods of war and famine.
It is unsurprising, then, that there should be shrines (and one temple) around the country that celebrate and venerate the sweet potato, as well as the people who brought it to their communities. Some of them are named for the tuber, as indicated by the word ‘imo’ in the name.
Note: ‘Imo’ can be translated as ‘tuber’ or ‘taro’. In Hokkaido, the word usually refers to potatoes (jaga-imo), but in the rest of Japan, it is more typically used as a shorthand for sweet potatoes (Satsuma-imo and all related varieties, such as Anno-imo, Naruto Kintoki, Beni-Haruka, Quick Sweet, Murasaki Imo, etc).
Noguni Sōkan Shrine, Okinawa
Before they arrived in Japan, sweet potatoes were first introduced to Ryūkyū (present-day Okinawa) by government official Noguni Sōkan. He had been studying Chinese texts on farming and agriculture while stationed at a trading depot in Fuzhou, and encountered a new (to him) potato plant that had arrived in China a few years earlier from other merchant traders. In 1605, he returned to his village bearing seedlings from Fujian, and planted them there. Within 15 years, sweet potatoes could be found growing across all of Okinawa.
During the same years, these tubers made their way to Japan through several channels. One was as a gift from Okinawan ruler King Sho Nei to the Satsuma Domain around 1611. In 1615, the “English Samurai” William Adams sent a bag of sweet potatoes to the unfortunately-named Richard Cocks, then-director of the British East India Company’s outpost in Hirado. Cocks planted these in a garden, making this the first recorded cultivation of sweet potatoes in Japan.
In 1789, the Ryukyu government bestowed samurai status on Noguni’s family as a way of recognising his contribution to the nation’s welfare. While he didn’t live to enjoy this munificent gesture, he would probably have been pleased to know that one can still visit the shrine that deifies him — Noguni Sōkan Shrine in the town of Kadena.
Tokkō Shrine, Kagoshima
In the early 18th century, 22-year-old Maeda Riemon of Ibusuki (Satsuma, present-day Kagoshima) encountered sweet potatoes for the first time on his visit to Ryūkyū, and loved them so much that he brought a basket of them home to plant in his garden.
He wasn’t the first to bring them back — in 1698, the feudal lord of Tanegashima had already sent a messenger to Ryukyu for sweet potatoes — but he was probably the first to share the crop with his neighbours, who took to cultivating their own afterwards. Sweet potatoes then spread across the Satsuma Domain, saving untold numbers of people from starvation. This is part of the reason sweet potatoes are commonly known as satsuma-imo; other names for this root vegetable include ‘kara-imo’ (Chinese potato), ‘Ryukyu-imo’ (Ryukyu potato), and Noguni-imo.
Unfortunately, Maeda perished at sea two years later, but was not forgotten by the grateful people of Satsuma Domain. They erected a stone monument for him (it reads ‘kara-imo don’ or ‘Lord Sweet Potato’), and later, built Tokkō Shrine in Yamakawa, Ibusuki, and deified him there. The shrine is sometimes referred to as ‘Kara-imo Jinja,’ or Sweet Potato Shrine.
Kon’yō Shrine, Chiba
On 9 March 1735, the eighth shogun Tokugawa Yoshimune received a proposal with an intriguing title: 蕃藷考 Banshokō, or ‘Thoughts on Barbarian Taro.’ Penned by a scholar named Kon’yō Aoki, the treatise described a new food source that had been instrumental in helping the islanders of Ōmishima in the Seto Inland Sea escape the effects of the Kyōhō famine of 1732 to 1733.
This treatise impressed Yoshimune — enough to make Kon’yō the official ‘Satsuma-imo commissioner,’ elevating him from a commoner to a samurai. In this new position, Kon’yō oversaw experimental sweet potato cultivation at Koishikawa Botanical Garden, as well as at the villages of Makuwari and Fudōdō in what is now present-day Chiba. His successful experiments led directly to the mass-cultivation of the tuber, meaning that the country no longer needed rice to be the only staple agricultural crop.
Just over a century later, in 1846, Kon’yō Shrine was established in Makuwari (now Makuhari) to commemorate his sweet potato success and contributions in alleviating famines in this area. There is also a monument at the original experimental sweet potato field, which is now a designated Prefectural HIstoric Site.
Imo Shrine, Chiba
Far less historic than the shrines introduced so far — but still kind of cute — is Imo Shrine in Katori, Chiba, which consists of a small torii gate and a large sculpture of a sweet potato flanked by two statues of Kuri-chan. Kuri-chan is the sweet potato mascot for the Kurimoto Roadside Station next door, which sells sweet potato soft-serve ice cream.
The shrine is probably best visited during the Kurimoto Furusato Sweet Potato Festival, where visitors can join a potato-digging event, sample the local benikomachi variety for free, and stock up on all the sweet potatoes you could ever want.
Imo Shrine, Saitama
15 years after Kon’yō Aoki succeeded in cultivating sweet potatoes in large quantities, news of this miracle tuber reached the village of Minami-Nagai in the Kawagoe Domain (present-day Tokorozawa City, Saitama). Recognising a good thing when he heard it, village headman Yoshida Yaemon sent his son Yazaemon on a journey to Kazusa, Chiba, to learn how to grow sweet potatoes. The son returned to Minami-Nagai with 200 seed potatoes, and after planting them, successfully harvested their first crop in the summer of 1751.
Not only would these sweet potatoes become a famine-proof crop across the rest of the Musashino Plateau, they would also become a cash crop for farmers, who could make a living through supplying the many sweet potato vendors operating in Edo from 1793 onwards. Since Kawagoe was only 30 kilometres away from Edo, shipments of fresh sweet potatoes — colloquially called ‘Kawagoe imo’ — came down to the city along the Shingashi River every day.
For his contributions, Yoshida Yaemon has been deified alongside Kon’yō Aoki as the Gods of Sweet Potatoes at Imo Shrine, a subsidiary of Shinmeisha Shrine. This enshrinement was relatively recent, taking place in 2006, and was accompanied by a sweet potato-planting ceremony and the installation of the Nade-Imo (a bronze sweet potato sculpture you stroke for good luck). The guardian lion-dogs also hold sweet potatoes, which is a very cute detail. Shinmeisha sells imo-themed lucky amulets (of course) and distributes 2,000 baked sweet potatoes free of charge to worshippers every January 1 and 2.
Kawagoe remained one of Japan’s major sweet potato producers until the 1960s. Tourists could even go dig sweet potatoes for fun; as a form of tourism, this peaked in the 1970s. Today, visitors can look around the Mini Sweet Potato Museum, drink beer made from sweet potatoes, thank the local Sweet Potato Jizo deity at Kawagoe Myozenji Temple on 13 October, or buy a sweet potato-themed fortune slip from Kawagoe Hikawa Shrine.
Ryūsenji Temple, Yamanashi
Some two decades after Yoshida Yaemon’s landmark planting of sweet potatoes in his village, news of this root vegetable reached a certain Nakai Seidayū, the magistrate of Kofu. He had taken on the position in 1777, but was then straightaway forced to reckon with the effects of devastating floods in 1778, followed by the Tenmei famine of the 1780s. There was widespread starvation and suffering, and he had to act fast.
In 1784, Nakai obtained shogunal permission to import seed potatoes from Kyushu. These were planted across all villages; he devoted the rest of his tenure to promoting the cultivation of sweet potatoes throughout the Kai Province and beyond. Sweet potatoes continue to be referred to as ‘Seidayu imo’ or ‘Seida imo’ in this region, highlighting the impact he had on this region.
Nakai was venerated as the Great Shining Sweet Potato Deity (Imo Daimyojin) at Ryusenji Temple in the city of Uenohara until the early 20th century, along with an annual sweet potato festival. There seems to have been an interlude of fifty years or so where this festival fell to the wayside. However, on 4 October 1981, the temple’s parishioners erected a new monument to him, along with a commemorative stone detailing his contributions to history. The annual festival also appears to have been resurrected.
On a related note, there is a local Uenohara dish called Seida no Tamaji, traditionally made with sweet potatoes too small to sell at market. They’re first deep-fried whole, their skins left on, then simmered in broth with miso, sugar, and mirin until the potatoes have absorbed all the liquid. It is probably best enjoyed with Imo Daimyojin, a shochu made from — you guessed it — Seida imo distilled with rice koji.
Hoshiimo Shrine, Ibaraki
These days, sweet potatoes are cultivated across Japan. Ibaraki Prefecture is the nation’s top producer of dried sweet potatoes; at 90% of the national supply, no other area comes close. It stands to reason that there is a shrine associated with the stuff. Enter Hoshiimo Shrine in Hitachinaka, Ibaraki. This is a relatively new shrine built in 2019, and supposedly enshrines five people who popularised dried sweet potatoes in the region.
Hoshiimo Shrine is a favourite on social media for its eye-catching golden torii gates — which, of course, are supposed to evoke sweet potato flesh. Additionally, ‘hoshi-imo’ (dried sweet potato) sounds similar to ‘hoshimono’ (things one wants), which implies that you might get what you want. (The Rolling Stones want a word.) Don’t forget to check out the dried sweet potato vending machine on the shrine grounds.
Written by Florentyna Leow