The nagamaki is considered to be a type of the no-dachi sword. It is a long sword with 2-4 foot single-edged blade and a handle of 2-3 feet length. Similar to the naginata, the main difference is that the handle (tsuka) of the nagamaki is not constructed of wood; it is made more like a katana handle. The nagamaki handle is wrapped with cords in criss-crossed manner, very similar to the wrapping that is made on katana.
The way to hold nagamaki is also very specific. It is held with the two hands in a fixed position in the same way a katana is held. Unlike the naginata, the hands don't change when handling the weapon and the right hand is always the closest to the blade. While handling nagamaki not too many sliding actions on the handle are performed as it is in naginata's case, where you use the entire length of the shaft.