Description
Kotaro Hyuga, a 23-year-old born in 1994 (Year of the Dog), stands 185 cm tall, weighs 78 kg, and has blood type AB. He serves as a director at his family's Hyuga Corporation, overseeing the "Marishi Machina" development project initiated by chairman Mitsukuni Hyuga. Kotaro's personality is defined by consistent clear-headedness yet profound solitude, underpinned by a fundamental distrust of others.

His past is inextricably linked to Dan Amo and Makina Mikage, their fates bound by their parents' earlier involvement in developing the Marishi Machina powered suits. One year after an incident at the Hyuga Corporation's Mount Fuji underground testing facility, Kotaro navigates the lingering consequences of their parents' actions alongside Dan and Makina. They strive to overcome these shared challenges, gradually strengthening their bonds while pursuing their individual paths.

A significant event unfolds when Makina unintentionally activates an incomplete Machina suit prototype, triggering a high-speed motorcycle pursuit involving Kotaro and Dan. This chase results in a serious accident for Kotaro. Following this, Mitsukuni Hyuga confronts Dan and Makina, revealing Dan's identity as the rider "Zebra" and disclosing the intertwined histories of their parents. This confrontation sets Kotaro, Dan, and Makina on a path to confront painful past traumas and face difficult personal trials tied to their family legacies and the Machina project.

Kotaro actively participates in testing the Marishi Machina suit at the Mount Fuji facility. This test, proposed by Mitsukuni, aims to unlock secrets concerning the fates of Dan and Makina's parents. His involvement is driven by his role in the suit's development and complex familial obligations. His competitive nature emerges during pursuits, particularly against Dan ("Zebra"), where he leverages the Machina suit's technology, driven by a desire to prove its capabilities against Dan's innate riding talent.

Beyond his corporate and technological responsibilities, Kotaro maintains an interest in tennis as a personal hobby.