Gyuki is a mystical creature appearing in the anime series "Yuuki Yuuna wa Yuusha de Aru." This character is not a human but a divine beast that serves as a familiar to the heroes, particularly aiding them in their battle against the Vertexes. Gyuki's role is crucial as it supports the heroes by providing guidance and occasionally power boosts during critical battles. Despite its fearsome appearance, Gyuki is a loyal companion and protector, symbolizing the strength and determination needed to safeguard humanity in the series.