These are called Tofu, made of soy bean, and are sold in supermarkets. Tofu, roughly speaking, has two kinds: Momen and Kinugoshi Tofu.
Momen feel a little rough touch and Kinugoshi feel a soft and silky touch and I prefer Kinugoshi.
Momen has less water than Kinugoshi but contains more protein, calcium, iron(Fe). Kinugoshi, on the other hand, contains more kalium and vitamin B1.
I often use Kinugoshi for cooking miso soup, Yudofu or boiled tofu, some Chinese cuisine. When I go to supermarket in the late evening, Kinugoshi is often sold out, though Momen is still left. Kinugoshi seems to be more popular than Momen in Tokyo.