Bara-zushi from the Okayama Prefecture consists of one plate of sushi rice with many toppings.
Ikeda Mitsumasa in Bizen (now Okayama) was a Japanese daimyo (territorial lords) of the early Edo-era. He banned the luxury life of his people, so he ordered 1 miso soup + rice + side dish meal.
People had the idea that many toppings should be put on the bottom of the wooden bowl, then covered with sushi rice. If nobody was watching, they turned the bowl upside-down and enjoyed the Bara-zushi.
The Japanese sardine is officially called sappa or kiiwashi. They livs in the Setonaikai Sea of Japan along the estuaries of rivers. They are about 20 cm long.
They often are eaten together with the fish konoshiro or tsunashi, another small herring.
Mamakari dishes are only prepared along the coastlines of the Inland sea, especially in Okayama. The fish itself is found along other coastal areas, where it has a lot of different names.
It is caught all year, but the best SHUN is from February to April. Most often eaten with some vinegar preparations.
The intestines are taken out and it is kept in salt and vinegar before consumption. Sanbaizu vinegar is quite popular with this fish.
The whole fish, with a few cuts in both sides in the flesh, can be deep-fried as karaage too, eaten with head, bones, and all. Nanbanzuke is prepared to fry the filets in oil before preserving them in vinegar.
The name Mamakari, comes from needing to borrow rice from your neighbors.
The famous author of the Meiji-era, Narushima Ryuboku (1837 – 1884) wrote in his diary from Okayama in 1869 :
“It looks like a small herring. When a fisherman catches it and brings it home to eat, it tasts very well. When he has finished all the rice at home, the wife goes to the neighbor to borrow some cooked rice and they continue eating. Hence the name.”
Others say the fishermen used to grill the fish right on their boats and when the rice of one boat was eaten, they would drive to the next one and ask for his to share.