In 2035, where robots are commonplace and abide by the three laws of robotics, a technophobic cop investigates an apparent suicide. Suspecting that a robot may be responsible for the death, his investigation leads him to believe that humanity may be in danger.

Using massive piloted robots to combat the alien threat, earth's survivors take the fight to the invading alien force lurking in the depths of the Pacific Ocean. Nearly defenseless in the face of the relentless enemy, the forces of mankind have no choice but to turn to two unlikely heroes who now stand as earth's final hope against the mounting apocalypse.

It has been ten years since The Battle of the Breach and the oceans are still, but restless. Vindicated by the victory at the Breach, the Jaeger program has evolved into the most powerful global defense force in human history. The PPDC now calls upon the best and brightest to rise up and become the next generation of heroes when the Kaiju threat returns.

住在踯躅台的高中1年级生响裕太，某天醒来后失去了记忆。 之后，裕太与旧电脑里显现出来的“Hyper Agent·古立特”相遇了。 古立特告诉裕太“去完成使命”，而裕太则开始寻找这番话的意义以及自己的记忆。 虽然对这一突发事件感到困惑，裕太仍然在同班同学内海将以及宝多六花、新条茜等人的帮助下过着每一天。 然而，平稳的日常被突然现身的怪兽轻易地踏碎——。