Kongōseki's body is a black, carbon fibre reinforced polymer staff, approximately 1.8 m long.
On it's stored form, it breaks into two, taking the form of a pair of half-staffs.
From within each half, a straight single edged blade of aprox. 50 cm long, can be entended. Those, each half can be used as a sword.
Alternatively, only one or both blades can be extended while both halves are joint, allowing to create either a spear or a double-ended polearm.
The halves can be joint to have the edges of the blades facing either the same or opposite directions.
Kongōseki has room to store one type of powdered dust on each half.
The dust can then spread its effect through the blade or from the blunt end of the staff.
- Kongōseki, written 金剛石, means "diamond" in Japanese.