Aspired to become an animator simply because he wanted to draw for a living. Later enrolled to and graduated from Tokyo Animator Gakuin. He then joined [Magic Bus](https://anilist.co/studio/207/) and debuted as an in-betweener in 1987 under the studio's name on [God Bless Dancougar](https://anilist.co/anime/5266/). Nakazawa soon left Magic Bus and went freelance. In 1993, he was involved in the establishment of Studio G-1, an animation studio founded by [Masami Oobari](https://anilist.co/staff/100660/). During his time there he participated in many of [AIC](https://anilist.co/studio/48/)'s productions. Nakazawa got strongly influenced by Oobari during this time due to working under him on multiple occasions. Also unlike most animators at the time, Nakazawa wasn't really that shaped by [Yoshinori Kanada](https://anilist.co/staff/106398/)'s style, he was though, a huge fan of [Ichirou Itano](https://anilist.co/staff/103268/)'s and [Yoshikazu Yasuhiko](https://anilist.co/staff/97220/)'s.

In 2002, Nakazawa made his directorial debut with Comedy, part of an anthology titled [Sweat Punch](https://anilist.co/anime/1072/), produced by [Studio 4°C](https://anilist.co/studio/13/). The following year he directed both [Parasite Dolls](https://anilist.co/anime/1350/) jointly with [Naoyuki Yoshinaga](https://anilist.co/staff/115038/), as well as the animated part in Quentin Tarantino's movie, Kill Bill: Volume 1. This brought him a lot of international praise. He then got reached out to by director [Shinichirou Watanabe](https://anilist.co/staff/97009/) of [Cowboy Bebop](https://anilist.co/anime/1/) fame, about the possiblity of taking part in the director's next work, [Samurai Champloo](https://anilist.co/anime/205/). Nakazawa accepted the offer and ended up being a crucial part of its production, handling the character designs and serving as the sole chief animation director on the show. He also directed, storyboarded and wrote the 15th episode. Ten years later in 2014, Nakazawa collaborated with Watanabe for the second time on [Terror in Resonance](https://anilist.co/anime/20661/), providing the character designs and working as an animation director on the series. In recent years he has been closely involved with [Production I.G](https://anilist.co/studio/10/).