“Tsukemono” is a general term for Japanese pickled vegetables. They are made by preserving vegetables in salt, rice bran, miso, koji, soy sauce, vinegar, and other seasonings. Depending on the pickling method and duration, both the flavor and aroma—and even the texture of the vegetables—can change significantly.
A well-known example is “takuan.” Takuan is made by fermenting dried daikon radish in rice bran and salt over a long period. It is known for its deep umami flavor, bright yellow color, and firm, crunchy texture.
In contrast, the word “shinko” originally referred to freshly pickled vegetables—lightly pickled items with a short curing time. These quick pickles are typically ready in a few hours to a few days. They are low in salt and preserve the natural crispness, juiciness, and fresh aroma of the vegetables. Over time, however, the meaning of “shinko” has broadened, and it may also refer more generally to pickled vegetables, including fully fermented ones like takuan.
“Oshinko (お新香)” comes from “shinko (新香)” with the honorific prefix “o- (お).” While it originally referred to lightly pickled vegetables (asazuke), it is now commonly used in everyday Japanese to mean pickles in general. In restaurants, it often refers to a mixed assortment of pickled vegetables.
This terminology also appears in sushi. A thin roll filled with takuan, wrapped in vinegared rice and seaweed, is called “takuan maki.” It is also known as “shinko maki” or “koko maki.”
Strictly speaking, from an etymological point of view, if the filling is a fully fermented pickle like takuan, “koko maki” would be more accurate than “shinko maki.” However, in modern usage, “shinko-maki” is far more common.
In simple terms: “Shinko originally referred to lightly pickled vegetables, where the short pickling time preserves their natural crunch and freshness. Today, however, oshinko is commonly used as a general term for pickled vegetables.”