The Hassanu are a people living in the northern, mountainous region of Nihon-Ja. They are often larger than two metres, dark-skinned, mostly redhaired and have prodigious amounts of body-hair. They are supervised by Lord Nimatsu. They live in the land north of the large lake and the Uto Forest. It is also rumored that the Hassanu are fond of sweets.

The Hassanu are a part of Nihon-Ja. They just isolated themselves for a long time.

The Hassanu fell out of memory of most Nihon-Ja for years and the Nihon-Ja began to believe that the Hassanu were ferocious monsters. In truth, they were a rather peaceful people, but when they were rallied for war, there was reason to fear them.

When Emperor Shigeru fought against the Senshi Warriors, the Hassanu helped the Imperials at the Battle of Ran-Koshi. The Hassanu have always feared the Kyofu, which means "the Terror". They believed it to be a demon. However, it later turned out to be a massive man-eating snow tiger.