Kucy is a shapeshifter who works as an assassin for Zorzal's force. She first appears as a disguised citizen with dozens of Imperial Soldiers to ambush Tomita's group. After all her comrades are slaughtered after Tomita detects their fake ID number, she is taken by Tomita since he mistakes her as a captured citizen.
After the whole ambush operation conducted by Herm against Tomita's squad failed miserably with the death hundred of Black Dogs, orcs and three ogres from Tomita's squad attacks as well as JSDF air support, Herm commands her to attack Tomita's squad through the special flute to give the JSDF some trouble out of frustration for his failed attack. After Tomita's squad and Komuzaraki's crew were being evacuated in the helicopter, she changes into her breast form and impales the cameraman, Fukushima with her claws, pushing the sound technician Marazaki to his death out of the helicopter's rear door and attacking Tomita's squad. At this stage, no one dares to shoot her since it will mean damaging the engine of the helicopter, which can lead to crash landing.
As the result, Shino engages her in hand-to-hand combat with her combat knife and manages to injure her right arm by damaging her relaxing muscle that balanced the movement of the arm. Shino then asks the pilot to reverse the helicopter to make Kucy off balance. When Kucy smashes her face on the ground of the helicopter, Shino then shoulder throws Kucy to the edge of the helicopter. However, she still clings on to the edge of the helicopter and tries to grab Shino, which Shino reacts by headbutting Kucy in the nose. As agony coursed through Kucy’s nose, and it could not help but twist its head aside. In the moment that it jerked its body away, Kuribayashi scrabbled free of its vast body, then twined her legs around its neck and executed a choke from behind its back. In the face of this sudden reversal, Kucy tried to shake Kuribayashi off. It suddenly rose up and bashed its head against the ceiling. Kucy’s head and Kuribayashi’s body collided with the ceiling, Kucy’s massive body slid toward the open rear hatch with the unconscious Kuribayashi fell toward the outside as well. Tomita desperately lunged at Kuribayashi with Azuma and Tozu reached out to grab Tomita’s legs. By the narrowest of scrapes, Tomita’s fingertips touched Kuribayashi’s bandolier and tightened around it.
As Kucy keeps trying to cling to the helicopter with her left arm causing Tozu and the others who saw this to try to kick it off by lashing out repeatedly with their combat boots. At last, she meets her end when Tomita gives her multiple headshots with his pistol in which she falls dozens of feet below to her death.