It has been twenty years since the tragedy of Bugs 2 and is now 2619. In order to save his childhood friend, Yuriko, from an unknown illness, Hizamaru Akari was fighting in an underground arena in Bangkok.

In order to create a vaccine for the A.E. Virus, Annex 1 heads to Mars. Akari and the other crew members try to enjoy their time on the ship before they land on Mars for the life-threatening mission.

Annex 1 ends up a blood bath at the sudden appearance of the terraformars. Akari and Marcos go to get the medicine in order to deal with the situation they've been given, but find that the terraformars are in the room with the medicine, and they are destroying their supply of the medicine.

Shokichi and his division make it safely to Mars, however they are immediately attacked by the terraformars. The other divisions are also attacked, and since there is only one terraformar in sight for each division, they feel that the threat is minimal.

Marcos remembers his childhood in Gran Mexico. Sheila, who always smiled like the sun, is now gone. Marcos lets all of his rage explode against the terraformars, his eyes filled with tears of sorrow for his fallen friend.

The thing that jumped onto No. 2 Division's escape vessel was a strange terraformar with strangely developed legs. It then takes the controls and tries to fly off with the escape vessel while everyone is still aboard. Yaeko and the others prepare for the worst as they're trying to figure out why it knows how to fly the vessel.

Michelle and Akari battle the mysterious terraformars. After the battle is over, Michelle goes to change and Alex and Akari try to take a peek. A brand new act was about to start right there on Mars. Meanwhile, Asimov and No. 3 Division reach the mysterious pyramids, where they fight the terraformar that stole Elena's life.

Adolf and No. 5 Division head toward the main ship of the Annex in the rain. But then, they unexpectedly get rammed by No. 4 Division's ship, and are grounded. While getting ready to face the horde of terraformars outside, Adolf remembers his past. He remembers his sad past, undergoing the M.O. operation... and then one day, someone changed his life forever.

Fierce lightning rips through the terraformars, as though it was an act of God. Adolf gives it everything he has, and collapses. Eva comes to his side. However, the safety felt from this victory was short. The boss of the terraformars is brought back to consciousness and they use all of their power to attack the No. 5 Division.

The No. 1 Division were spread apart because of the Terraformars. In the depths of a dark hole, the gong had rung on a battle of the Earth vs. Mars. On Mars's side, a weevil-based Terraformar and on Earth's side, was Onizuka Keiji! He had always lived a very simple life. In order to protect the island his mother loved, and to protect his precious new friends, Onizuka stands in the ring yet again. Thus begins the brutal and unrelenting battle of fists.

After being surrounded by the thread that a Terraformar with the powers of a silkworm laid out, Shokichi remembers Akita Nanao. Shokichi regrets the fact that they had to leave her body behind on Mars after they had killed her during the Bugs 2 mission. Now, he wants to get revenge. Will Shokichi be able to restart the clock that had stopped twenty years ago? Meanwhile, The No. 3 Division is within the pyramids and find something that shouldn't be there, and suddenly, a deafening sound can be heard throughout Mars.

The No. 1 Division finally comes to No. 2 Division's aid in their most desperate hour. Michelle and Akari both use their BUGS powers and face off with the Terraformars. Because they are reunited, the truth of Sheila's death also comes to light. Meanwhile, the presidents of the allied nations was meeting with the prime minister of Japan, Hiruma Ichiro. The Annex crew is about to face the true test of survival!