On your travel in Japan, you would probably notice: no matter where you go you will find boxes of sweets for souvenirs. Perhaps the most common kind is o-manju （お饅頭）, which is a small steamed cake containing paste of sweet beans ("anko")
Also, in Tazawako, there are many different types of o-manju boxes available for your souvenir. You can find them at souvenir shops like Tazawako-ichi, Tazawako Kyoei Paresu, Tazawako Rest House, etc. And you can find specially designed ones at hotels, too.
Mizusawa Onsen's O-manju, the white anko (bean paste) is good!
Rotenburo Mizusawa Onsen gives away the special o-manju only four times a year. During the Tazawako Snow Festival at Tazawako Ski Area (only a few minutes away), the popular hot spring facility welcomed guests with a free o-manju! Theirs are bigger than the average size and specially made by a local pastry shop, Masaki Kashiya (near JR Tazawako Station).
Kashin-tei Shirahama （花心亭しらはま） is one of the most exquisite hotels on Lake Tazawa. While they accommodate more than 80 guests in their 5-story building, they give you the most personalized care and relaxing moment with the most beautiful view of Lake Tazawa.
The o-kami-san (lady manager) of Shirahama, Ms. Yuko Yamate, is a very nice lady and has a sophisticated sense of hospitality. Even this tiny o-manju designed by her can tell you so much about it: white and delicate sponge containing kabocha (Japanese pumpkin) paste with the salty dry sakura (cherry blossom) on the top! It’s delicious and goes perfectly good with your green tea!