Starting his career at the now-defunct game company Cavia, his best-known work was on the action role-playing video game series Drakengard, and its spin-offs, Nier and Nier: Automata. Yoko was born in Nagoya, Aichi, and studied at the Kobe Design University in the 1990s. While he did not initially intend to pursue a career in video games, after working at Namco and Sony, he joined Cavia and became the director and scenario writer for the first Drakengard game.