Fubuki Sakuragasaki is a powerful gamer who, with the power of her Passion Panties, climbs up the ranks of the BAG (Best of Arcade Gamer) tournament to become the greatest Arcade Gamer in the world. However, the evil Gulasic Group is out to conquer the world through said tournament, and their gaming skills will prove to be a challenge. Fubuki must team up with the legendary Mr. Mystery to combat the four Gods of Gaming and make the world of arcade gaming safe for all.

Doppo Orochi sits down to watch the final match of his karate school's youth tournament. Atsushi Suedou, one of his disciples, faces off against Baki Hanma, a fresh teenage boy breezing through the matches. Intrigued by the boy's strength, Doppo, alongside another of his disciples—Kiyosumi Katou— visits the notorious Tokugawa underground ring—a hidden freestyle fighting arena that prohibits only weaponry in its matches. Upon arriving, they learn that Baki is set to face none other than Koushou Shinogi: an infamous karate master and user of the lethal Cord-Cutting technique.

To save the Earth from alien invaders and their giant monsters, Dr. Kishida does what any other red-blooded mad scientist would do: he builds a giant robot—the ultimate feminine fighting robot! Unfortunately, his grand-daughters refuse to pilot it! Apparently, they've got more important things to do than becoming teenage super-heroes. Besides, how are you supposed to study for your college entrance exams while getting beaten-up in battle? Fortunately for Dr. Kishida, things aren't too well for the invaders, either. According to their reports, the Earth was the perfect target: lush, peaceful, and relatively defenseless. Theoretically, the planet should've surrendered long ago. Now, the war is at a standstill, the dreaded Accounting Department is warning about the serious cost overruns, and the head of the home office has arrived from Galactic Headquarters to personally oversee operations. Has Headquarters decided to unleash, The Audit—or do they have something even more evil in mind? The fate of the world rests upon two people: Aya Kishida, one of the doctor's granddaughters, who may have to give up prep school to pilot the mighty (and lovely) ARIEL; and a mysterious alien named Saber Starblast, who may have the power to defeat the invaders once and for all...

Those incompetent aliens are still plotting to conquer the Earth! The only obstacle in their path is the giant, feminine robot ARIEL! But the young pilots have lives of their own... When Kazumi receives a mysterious love letter from a secret admirer, should she cancel her first date just to save the Earth?