Sushi was not always what it seems like today. The word sushi originally means fermented fish, and has its roots in Southeast Asia. According to the history of sushi, this type of sushi is first seen in Japanese scriptures in the 7th century. Later on, the fish were stuffed with rice before they were fermented, and this is called the nare sushi and is the earliest form of sushi in Japan. Nare Sushi took a couple months to prepare, and eventually becomes consumed before the fermentation process is complete. This is called the nama nare sushi or "raw" nare sushi (left image). This made the rice, which acquires a sour taste from the fermentation process edible since longer fermentation dissolved it. It is not until the 19th century when the Edo style sushi, or the sushi commonly known today was invented. The sour rice was mimicked by mixing fresh rice vinegar to make sushi rice, and fresh raw ingredients were used instead.