Hokkaido Nagaimo is yams produced in Hokkaido's Tokachi district, and are a variant of the short Yamatoimo which look like a sake bottle. Their skin and flesh are both white, and do not brown easily. They offer a crunchy texture, are pleasant to eat, and when grated into tororo, they are very sticky.

The Nagaimo is sometimes referred to as "mountain medicine" (Shan Yao) and is used for medical purposes in Chinese medicine.

It is also known to help reduce high blood pressure, regulate digestion and relieve fatigue. It may help lower cholesterol levels and acts as a tonic for general vitality. Since Nagaimo contains high levels of amylase and other digestive enzymes, it can help to digest starchy foods, such as rice eaten with it.