Mentsuyu, made by adding soy sauce, sake, mirin, sugar, and other seasonings to soup stock made from kelp, shavings, and etc., is a seasoning that has evolved along with the development of Japan's noodle culture.
It is now an essential ingredient in a variety of Japanese dishes, used not only as a dipping sauce for soba, udon, and tempura, but also as a seasoning for simmered dishes and rice bowls.
There is a straight type to be used as is and a diluted type to be mixed with water.

It is commonly used as a dipping sauce for soba, udon, somen and other noodles, as well as for tempura and other dishes.
Since tsuyu contains soy sauce, sugar, mirin, and dashi, it is useful as a versatile seasoning that deepens the flavor of a wide range of dishes, such as Kinpira Gobo and Niku Jaga, and other stewed dishes, as well as Oyakodon, Katsudon, and other rice dishes.  

This sauce was created by adapting Worcestershire sauce, which was brought to Japan from England at the time of civilization, to Japanese tastes. It is made from a variety of vegetables, fruits, spices, and vinegar. There are many types of sauces that are specialized for use in various dishes, such as Chuno sauce, Tonkatsu sauce, Yakisoba sauce, Okonomiyaki sauce, and Takoyaki sauce, which are mainly used as "Tare” or “dipping sauces" for deep-fried foods.

This sauce was created by rearranging the British Worcestershire sauce, which was only used to add a few drops of flavor to dishes, into a seasoning to be "dipped or poured" like soy sauce. It is therefore generally poured over cooked dishes.
On the other hand, it is also widely used as a "secret ingredient" in curry rice, Japanese hamburgers, pasta sauce, and other dishes.

A soup made by boiling kelp, dried bonito flakes, dried sardines, and etc., in water.
Its history goes back as far as the Nara period (8th century), when a document records that "dried bonito flakes (or some other ingredient believed to be bonito flakes) were presented to the Imperial Court.”
Dashi is the backbone of Japanese cuisine, as it adds “umami” to various dishes through the action of glutamic acid, inosinic acid, and guanyl acid, which are types of amino acids.

Dashi is used in various dishes such as miso soup, soup, simmered dishes, Takikomi Gohan, and Dashimaki Tamago (rolled egg), but it is also used as a base for "tsuyu" for soba, udon, and somen noodles when combined with soy sauce, sugar, and mirin.
On the other hand, the dashi broth's flavor can compensate for the saltiness of dishes, and in recent years it has attracted attention as a seasoning that can help improve health.

A paste-like seasoning made by fermenting and aging steamed (or boiled) soybeans with malted rice and salt.
There are various theories as to its origin, but the most popular theory is that it developed in Japan based on the ancient Chinese seasoning "Hishio" (soy sauce).
Miso can be classified into "Kome (rice) miso," "Mugi (barley) miso," and "Mame (soy) miso" depending on its ingredients. It can also be classified into "Ama (sweet) miso", "Ama-kuchi (mild) miso", and "Kara-kuchi (spicy) miso" according to taste, and "Aka (red) miso", "Awa-iro (light) miso", and "Shiro (white) miso" according to color.

Miso soup is a widely popular Japanese cuisine. It is made by mixing miso paste with soup stock made from dried sardines (iriko) and dried bonito flakes, and adding vegetables, tofu, wakame seaweed, shijimi clams, and other ingredients of your choice.
In addition to miso soup, miso is also used to flavor a variety of other dishes, such as "mackerel stewed in miso" in which mackerel is simmered with miso, sugar, mirin, and other ingredients, and "miso stewed udon" in which udon noodles are stewed in miso-dissolved broth.