Daizaburou Higashiyama, an ordinary high school student, inherits a legacy entwined with an ancient robotic entity following the death of his father—a scientist whose pursuit of extraterrestrial technology led him to unearth a buried mecha, only to perish during the expedition. Reluctant and unprepared, Daizaburou assumes the role of the entity’s pilot as hostile alien forces emerge, threatening Earth’s survival. Initial self-doubt and the crushing weight of responsibility clash with escalating battles, forging his resolve.

Alliances with military operatives and fellow pilots challenge his perceptions, teaching him the harsh realities of leadership and sacrifice. Bonds with family members linked to the mecha’s origins anchor his determination to shield others. Fragmented flashbacks and his father’s recovered research notes unravel secrets about the entity’s latent capabilities and the aliens’ true motives. Through trial and combat, Daizaburou hones the mecha’s evolving power, his growing strategic prowess mirroring his inner confidence.

Loss and moral quandaries in the heat of war force him to confront the human toll of conflict. Critical decisions under fire mark his transition from hesitant defender to proactive guardian, prioritizing unity and trust in allies. Each struggle strips away his uncertainty, culminating in a transformation from a reluctant teenager to a resolute protector, harmonizing fragile humanity with the inexorable pull of destiny.