This is SHIRO MISO, a white miso paste. This white miso paste has a very sweet and creamy taste and less Sodium (about 5%/vol.) content than other miso pastes. Most other miso contain around 12-13% Sodium.
It's also called SAIKYO MISO, which this miso originally came from Kyoto area and used a lot for delicate, artistic, and traditional food dish - KYO-KAISEKI（京懐石）.
I love this sweet tasting miso. When I make miso soup, I usually mix this miso with another miso to make more flavorful miso soup, and shiro miso gives a pleasant sweetness, and using this white miso for miso soup in the winter time is very comforting.
Since this miso has less sodium content and is a smooth paste unlike other types of miso paste, it is also useful and easy to use for a marinade or dressing.
There are hundreds of miso companies in Japan, their taste and flavors all very with each company and the region they are located in, which gives each miso their own unique flavor due to the ingredients and the way they are processed for fermentation.
So, I love to try different types and brand of miso every time when I buy a new one.
It's still cold in northern Japan, so I hope that all the local people who are living in the evacuation area have some nice hot miso soup...