Toshiyuki Horii is a Japanese mechanical designer and concept artist recognized for his contributions to anime productions, particularly within the mecha and super robot genres. His professional credits, spanning from the mid-1990s to the early 2020s, establish him as a specialist in the design of robots and mechanical elements for animated works.

One of Horii’s earliest noted credits is as a mechanical designer for the 1994 anime OVA series Otaku no Seiza, an adaptation of the manga by Mitsuteru Yokoyama. This was followed by work on Ultraman Chōtōshi Gekiden in 1996, where he again served as a mechanical designer. In the mid-2000s, he contributed as the original mechanical design concept artist for the 2005 series Gunparade Orchestra, and in 2007, he took on the role of mechanical designer for Steel God Jeeg, a remake of the classic 1970s series.

His credits in the 2010s include serving as a mecha designer for Mazinkaiser SKL in 2010, an original video animation featuring the iconic Mazinger franchise. In 2015, he worked on Cyborg 009 VS Devilman, a crossover anime project, where his role was listed under the broader category of design works. One of his later prominent credits was as the robot concept designer for the 2021 television anime series Getter Robo Arc, based on the manga by Ken Ishikawa.

Across these projects, Horii’s body of work consistently focuses on the mechanical aspects of anime production. His career is defined by a specialization in mecha design for high-profile robot anime franchises, contributing to the visual development and mechanical aesthetics of both modern productions and remakes of classic series.