After BUGS1 was wiped out by the surprising life on mars, U-NASA deployed 15 people as a part of BUGS2 to go to Mars to investigate and if possible to exterminate the cockroaches.

After BUGS1 was wiped out by the surprising life on mars, U-NASA deployed 15 people as a part of BUGS2 to go to Mars to investigate and if possible to exterminate the cockroaches.

2620 AD. Humanity tried a terraforming project on Mars, which lead to super evolved roaches, as well as the Alien Engine virus, which has a 100% death rate. To break through this nightmare, a crew that had undergone a special surgery has been sent to Mars. Hizamaru Akari and Michelle K. Davis lead crew members with special powers to try to resolve both of these issues.

No. 4 Division gets to the main ship, but finds they've walked into a trap. The Chinese division has betrayed them, and wants the two post-surgery humans as experimental samples. The Chinese have brought weapons, which they use to slaughter the Terraformars by the hundreds.

The battle between humans is interrupted by a horde of thousands of angry aliens. Will the crew of Annex 1 be able to work together long enough to survive the onslaught of a new Terraformar general?

The Chinese division has revealed their ultimate weapon: a girl with an anthrax surgery base. Unless she's killed, there is no hope of defeating them and reclaiming Annex 1. Alexander goes in alone into the anthrax-covered spaceship to assassinate her.

Separated from the group, Michelle and Hizamaru are attacked by Terraformars using the powers of the other Mosaic operation subjects who died. Overwhelmed and outmatched, their only hope is to use a cunning plan to trick No. 4 division into destroying their foes for them.

Michelle and Hizamaru use their unique weapons to defeat the Terraformars who possess the powers of the former crew. Will their Ninja-vibro-blades and acceleration-boosted martial arts be enough to stand up against the superpowered Terraformars?

Michelle and Akari are kidnapped by Bao from No. 4 division. He tries to take them back to Annex 1, but to get there, he'll have to break through a horde of thousands of Terraformars. He decides to sacrifice Yaeko to get away. Will her non-combatant rank powers be enough to hold off the swarm?

The mighty rank 1, Joseph G. Newton, arrives to save Yaeko from the horde! He easily dispatches Bao and rescues Akari and Michelle. But will he be able to achieve his greatest objective... and win Michelle's heart?

The engineering team, led by a few lower-ranking combat soldiers, mounts a desperate assault on the bioweapon-infested Annex 1. The Terraformars attack at the same time, making for a disastrous 3-way battle.

The engineering team continues its strike on Annex 1, but the Terraformars have infiltrated the ship as well. With foes on all sides, both human and inhuman, will they be able to make their way to the control room and alert Earth to No. 4 Division's treachery?

The battle for the broadcast tower rages on as the civilian crew of No. 1 division infiltrates the control room. But the Terraformars are there two! If they make any noise the trained killers of No. 4 Division will hear them, so they're forced to continue their work in total silence as the killer cockroaches get every closer...

The heroic sacrifice of the civilian crew allows No.1 and No. 2 division to temporarily take back control of the communications tower. But the last member of the crew passes out before she can tell Earth about No. 4 division's betrayal. Is all hope lost, or is there another way?

The No. 1 and No. 2 divisions have walked into a trap set by the Chinese team. They manage to neutralize the Chinese' superior weaponry, but they still have a few tricks up their sleeve, and their transforming power is greater than it may appear!

So the crew have made it back to Earth, but the Terra Formars have too! Akari takes on a mission in Japan and things get heated up while Earth forces try to figure out how to stop the Cockroaches.

Earth forces continue to battle over the Pacific in defense of the islands there.