|This article is about a/an monster in Samurai Sentai Shinkenger.|
- "Onigatana nidan giri!"
- ―Ushirobushi whenever he uses his signature attack and also his final words before his initial defeat when unleashing it on all five Shinkengers in an underground car park.[src]
- "How dare you force me into this form!"
- ―Ushirobushi when he enlarged.[src]
Ushirobushi (ウシロブシ Ushirobushi, 11-12) is the most feared among the Ayakashi, armed with the Onikōbe Sekkeitō (鬼首楔形刀 Oni's Head Wedge Sword) that he uses in his Onigatana Nidangiri (鬼刀二段斬り Onigatana Two-Step Slash) attack, which is a combination of sound-waves leading into a multiple-slash attack which takes damage due to the set-up leaving the opponent open to attack. He is sent by Shitari to kill ShinkenRed, but Juzo Fuwa's interference forces him to fall back when he starts to dry up.
Ushirobushi later resumes his task, where the Shinkenger set up a strategy to hold him off. They defeat the Onigatana Nidangiri by having two members (Mako and Kotoha) block the sound waves, then two more (Ryunosuke and Chiaki) block the sword slashes before Takeru destroys him by the Two-Mode Transforming Rekka Daizantou Ozutsu Mode's Tora Five Rings Bullet. In his second life, the combination of himself and an army of Oozora Nanashi Company force ShinkenOh to it's knees and cause the Shinkengers to call upon DaiTenku to fuse with ShinkenOh and create the Tenku ShinkenOh for the first time, destroying all of them and finishing Ushiroboshi with the Tenku Bamboo Slice.
His upper body, which resembles an angry beast, is the basis of the Otoroshi (おとろし) of Japanese myth.