Mumei uses a pair of steam pistols that act on the same principal as the guns used by the Bushi. The exception being that each has a spring bayonet.
The bayonets are coated in a Kabane heart substance, making them able to pierce the hearts of Kabane and giving them extra durability. The pistols are loaded the same way as the steam guns. It is unknown how many shots Mumei can shoot but the guns have chronometer on their back to let Mumei know how much time she has used up. The pistols seem to also have a limited range and cannot fire as far as the Bushi guns.