Zenzai refers to stewed red beans sweetened with sugar that are served in a bowl with mochi (sticky rice cake), shiratama dango (dumplings made of sticky rice flour called shiratamako), and chestnuts stewed in sugar.
Generally, the word "zenzai" is used to mean the dish in which the grains of the azuki beans are discernible.
A shiruko, or a sweet azuki bean soup using koshian (azuki bean paste) is called 'zenzai with koshian.'
In the meantime, in the eastern part of Japan, the zenzai using tsubuan (the azuki bean paste with azuki chunks in it) is called "shiruko."
There are two theories about the etymology of "zenzai."
One theory relates the word with the Buddhist term 'Zenzai' (the kanji characters of which can also be pronounced as yokikana, meaning "good things.").
According to this theory, Ikkyu Sojun alleged to be the first person who ate the zenzai was so impressed with how tasty it was that he could not help shouting 'Zenzai.'
The 'zenzai' was the word used by Buddha to praise his disciples.
Another theory holds that the word derives from 'Jinzai (meaning "gods exist") Mochi' originated in the Izumo region. In the Izumo region, it is believed that October is the month when gods from all of the country gather in the area, and accordingly, the month is called 'Kamiari zuki,' meaning the month in which gods exist. Events called 'Jinzai Matsuri' are held at the Izumo- taisha Shrine in the first half of the month and at the Sata-jinja Shrine in the second half of the month. It was on this occasion that 'Jinzai Mochi' was handed out at the Sata-jinja Shrine.
Some argue that the word, modified with a local accent, came to be pronounced as 'zenzai.'
This is mentioned in the Gion Tale as 'People talk about the Jinzai Mochi in the Izumo Province,' with a description that 'it is a dish of stewed red beans with mochi in it,' suggesting that the Jinzai Mochi was something similar to the current zenzai. By the way, 'Jinzai' is pronounced as 'Zunzai' with the Izumo accent (In the Izumo region, the zu-zu dialect in which vowels are modified and pronounced as "u" is common. And the sound "zu" is not articulated). It is believed that people from other regions misheard 'zunzai' for 'zenzai', and this usage then spread to Kyoto. In fact, in the Izumo region, it is common to eat zenzai for the New Year soup dish called zoni. A product called 'Izumo Zenzai' has recently been released.
Zenzai in Okinawa Prefecture
In Okinawa Prefecture, 'zenzai' particularly refers to the ice candy. It is shaved ice with sweetened red kidney beans on top.
Originally, it referred to chilled mung beans stewed in sugar, which was also called 'sweet snack.'
After the World War II, the shaved ice on top of the kidney (or azuki) beans stewed in the syrup or with brown sugar became popular. Recently, the one with shiratama dumplings is common. The warm dish called zenzai in the regions other than in Okinawa is in Okinawa known as "hot zenzai," but it is not normally sold in Okinawa.
Zenzai in the Kanto Region
In the Kanto region where the dish known as zenzai in the Kansai region is called shiruko, 'zenzai' refers to the mochi or shiratama dumpling dish with a dry azuki bean paste. This dish is called 'Kameyama' or 'Ogura' in the Kansai region.