In a bid to thwart alien invaders and their colossal beasts, Dr. Kishida constructs a colossal robot named ARIEL - a formidable feminine warrior. Despite his best efforts, his granddaughters shun the idea of piloting it, prioritizing their studies and teenage lives over heroism. Meanwhile, the invaders face unexpected resistance on Earth, a planet they expected to conquer swiftly. As tensions rise and the cost of the conflict escalates, Headquarters dispatches an ominous figure to oversee the situation. Will Aya Kishida, Dr. Kishida's granddaughter, abandon her education to control the powerful ARIEL? And could an enigmatic alien named Saber Starblast hold the key to humanity's salvation?