Kanzaka was born July 17, 1964. He wrote fiction as a hobby with his friends; they would write in notebooks and trade them to offer criticism to each other.
Before becoming a professional novelist, Kanzaka worked in an office (the details of which he refuses to disclose, other than it was "boring" and he "was not a good worker"). In the late 1980s he noticed that Dragon Magazine was holding an amateur fiction contest. Being a fan of science fiction and fantasy, he decided to enter with the predecessor to what would be Slayers. However, he eventually changed the story's scenario, keeping some of the same characters but changing their roles in the story. This new version was Slayers, and his entry won first prize in the contest. The story was soon to be serialized in the magazine for over a decade, with its side series, Slayers Special, serialized in the magazine to this day. His friend Rui Araizumi has provided the series' illustrations since the beginning. Kanzaka attributes part of his initial success in breaking into the fiction world to another friend , also a writer.
In the early days of Slayers, Kanzaka kept his office job, but he spent much of his time dreaming up the scenario for his new series. He once related a story of him riding his bicycle home from work late at night, working out the incantation for Giga Slave aloud as he rode. He also admits that much of the first novel was not planned; for example, he claims that he had not come up with the character and role of Ruby Eye Shabranigdu, the primary antagonist of the volume, until approximately midway through the book.
When the Slayers anime began in 1995, Kanzaka's novels served as inspiration for director Takashi Watanabe, although Watanabe took some liberties with Kanzaka's original story. Kanzaka's job on the series was to approve episode scenarios and advise writers and directors on series canon. Kanzaka continued this job through 1997, when Slayers TRY ended, only to pick it up again in 1998 with the anime version of Lost Universe.
With no anime to supervise, Kanzaka currently concentrates on writing several novel series, including Slayers Special.
Kanzaka has an offical fan club, the Mega Brand Project, whose members previously produced the magazine Blaster!. Kanzaka is an avid sci-fi fan, and one of his hobbies is building Gundam models. He also loves cats, and sometimes carries food for stray ones in his pockets for when he goes on late-night walks. Kanzaka is a night owl, claiming that he usually wakes up in the afternoon and goes to bed at dawn. He says that he gets his inspiration for stories by going shopping or going for walks. He also plays card games with his friends, but he says he is not very good at them.
He says that he enjoys manga by Rumiko Takahashi, especially Urusei Yatsura because its characters are "attractive" and it is a "high-quality" comedy. He says his favorite anime is Mobile Suit Gundam, and that the series was a large influence on him.
Regarding Slayers, Kanzaka says he does not have a favorite character. He says that each character, even the villains, has some aspect of himself in him or her. He attributes the success of the Slayers anime in the United States to the established popularity of fantasy anime and role-playing games, on which Slayers is mostly based.