After defeating several Soul Reapers of the tenth division, Koga meets Hitsugaya. Koga summons his doll Dalk, who is quickly frozen and shattered by the shikai of Hitsugaya's zanpakutō. Koga fuses the remains of Dalk into an axe, and Hitsugaya uses his bankai in response. Hitsugaya injures Koga repeatedly, forcing him to absorb spirit particles to heal himself, but his body begins to reject the spirit particles. Koga makes a final attack on Hitsugaya, who slashes him, and Koga alludes to "a future without war" before collapsing.