The himuro was a place where ice was traditionally stored in Japan and corresponds to the modern-day refrigerator. Some geographic names reflect the existence of a himuro in the past.
It was necessary to keep winter ice so that it would not melt in the age when no technology for generating ice was known. Although no accurate records remain, ice is considered to have been kept cool in caves or a hole dug into the earth and covered, for example, with a thatch-roofed hut. Using this method, it was possible to keep ice until summer in cool mountain areas because the temperature in a himuro is cooler than that of the outside air due to the vaporization heat of underground water. During an age when only natural ice was available, only those in power, such as the imperial court and shogun families could use ice during the summer because it was valuable.
Historically, himuro is said to have initially appeared in the following description for the sixty-second year of Emperor Nintoku in "Nihon Shoki (Chronicles of Japan)" when Imperial Prince Nukata no Onakatsuhiko found a glittering thing when he went on a hunting trip to Tsuge (the present-day Fukusumi-cho, Tenri City, Nara Prefecture). Later, the family name of Hinomuraji also appeared in Kotoku-ki (Chronicle of Kotoku Emperor) of "Nihon Shoki," suggesting the existence of a job managing the himuro for the imperial court. For example, descriptions of hinomuraji and himuro are found in a family line diagram of the Agatanushi family of the Kamo clan, one of the families that occupied important positions in the imperial court (the family produced many priests, mainly at Kamo-jinja Shrine, and might have been a former local ruling family, and the god of Kamo-jinja Shrine was the clan deity of the Kamo family).
From among the mokkans (a mokkan is a narrow strip of wood bearing an official message) written by Prince Nagaya during the Nara period unearthed in Nara, one was found with the writing, "Tsuge-no-himuro (himuro at Tsuge)." Himuro and the position of managing it existed in every period (it belonged to Shusuishi (Water Office) of the Imperial Household Ministry when Japan was governed by the Ritsuryo system (a system of centralized government based on the corresponding code) until it was abolished in the Meiji period.
In the Edo period it was customary that the Kaga domain would present ice from a himuro to the shogun family on June 1 of each year. Himuro with earthen-walls came to be built even in the urban areas of Edo, making it possible to supply ice to the general public during the summer. Edo's drinking water was supplied by Tamagawa Josui Water Supply, but the water became warm in summer. Thus there emerged the business of the mizuya, which sold water cooled with ice. However, since the water to which ice was added was taken from a river, elderly persons who drank such water would often experience stomach upset. From this situation, the expression "an old man's indiscretions (one should act one's age)"emerged.
There is a Noh play that uses this as a theme and the title of the play. One of the Kojin-mono (Noh play with a fierce god) in Waki-noh Mono(Noh play with a god as the main character).
Modern-day himuro opening
The himuro hut is filled with snow (readying the himuro) on the last Sunday of January, taken out on June 30 (himuro-opening) and then in Kanazawa City and surrounding areas, people eat himuro manju (a bun with a bean paste filling), which is said to imitate ice, as they pray for good health on July 1. These events were discontinued in the third decade of the Showa period, but they were revived in 1986.
However, the area has been troubled with the lack of snow due to the warm winters of recent years, and the Hakuunro Hotel, which was the owner of the himuro hut, went bankrupt in 1998. The event was in danger of being terminated, but is still running to this day because of the approval of the bankruptcy administrator.
In Yatsushiro City, Kumamoto Prefecture, a himuro festival is held at Yatsushiro-jinja Shrine (myoken-gu) from May 31 to June 1. The festival day is customarily called "Koozzuitachi (perhaps meaning the first day for ice)" and people eat yuki-mochi (rice cakes imitating lumps of snow).