Age: 16
Kazuki attends a private academy with his sister. After getting involved in Tokiko Tsumura's battle and being killed, he is revived by a Kakugane. Despite being told to return to his normal life, Kazuki insists on helping Tokiko in her fights. He is enthusiastic and friendly, deeply caring for his friends and sister, Mahiro, often putting himself at risk to protect them. Though his feelings for Tokiko Tsumura are unconventional, they are genuine.
The Kakugane used to revive Kazuki was a Black Kakugane III, transforming him into a being similar to Victor. Consequently, he becomes a target for the "Muto-assassination team" and his former commander, Captain Bravo. During this time, he is labeled "Victor III" by the Alchemy Warriors. In a final act of sacrifice, Kazuki sends both himself and Victor to the moon using Sunlight Heart +. However, in the Buso Renkin Period, he returns to Earth with help from Victor's Buso Renkin, Fatal Attraction. Upon returning, he settles his score with Papillon, emerging victorious. Finally, he resumes a normal life with Tokiko.
