Prodigious Band. This weapon can be found by completing Ranmaru's 2nd Request on the 31st Floor in Survival Mode. To unlock this Request, you need to do Mitsuhide's first request (or was it second?).
31: Beat down officers to until you find 2 clues, then head for the stairs.
32: Take out all the Miscreants attacking allied units to gain clues
33: Deducing your clues, take the east stairs to chase after Keiji
34: Beat Keiji (take out some Strike Ninjas as they are annoying)
35: Beat down Ieyasu, then a Mitsuhide clone. Once you do this, another Ranmaru will give you a challenge. Now once he appears, you need to defeat him in under 3 Minutes in order to have him drop the weapon for you. You should be fine if you are around Level 40 or you got a good weapon.
![](https://s2.save4k.ru/pic/elBHDDRLVaw/maxresdefault.jpg)