Shiki and the gang get through Dragonfall and arrive at the Aoi Cosmos, which is ruled by Poseidon Nero of the Oración Seis Galáctica, and land on a fire planet, Red Cave, at the suggestion of Witch. The planet is overflowing with Water Ether, and is an environment that is a far cry from a "fire planet" covered by the ocean. As the Edens Zero crew enjoy a brief vacation at the ocean, they discover a town beneath the waters...!

Within a temple adorned by reliefs of Mother, Shiki and the group meet Nadia, the temple's guardian. They hear from Nadia that the far end of the temple contains hints to finding Mother, but as they venture deep into the temple, they find a scorching cave…

With Laguna's help, Shiki and the gang obtain a hint for finding Mother and leave Red Cave towards the Verdant Planet Foresta. Meanwhile, Elsie's pirate gang, cruising through the Aoi Cosmos on the Skull Fairy, are being pursued by Justice of the Cosmic Government's Interstellar Union Army.

The robots attack the ship and Jin, Kleene and Laguna have to defend their new allies. Meanwhile, on the planet, Shiki and the others are confronted by Poseidon Nero, who has been ordered to eliminate all robots.

Shiki confronts Orc from Poseidon Nero's Commando Team "Beast". Orc tells Shiki that they were ordered by Nero and are on a mission to cleanse this planet, which was under the control of Ziggy.

The battle in Foresta continues its course. Rebecca tries to experiment a little more with the use of Cat Leaper, but Hermit meets someone from her past that causes her to relive certain traumas.

The battle in Foresta rages on and Elsie springs into action to help Shiki when Justice cuts his way.

The Doomsday System is activated and all of Foresta is in danger.

Now that everyone's back on the ship, Shiki introduces Xenolith, who has some disturbing statements that affect Shiki and his companions. Meanwhile, Oceans 6, Poseidon Nero's group, assembles and prepares for their next move.

Under Xenolith's guidance, Shiki and his friends receive VR "bondage training" to overcome decline of Ether levels when they are constrained. During this training, Ziggy suddenly appears and hurts Rebecca with gravity, infuriating Shiki and causing him to break out of his constraints.

After Poseidon Shura's "Judgment Day" declaration, Shiki and his friends decide to think of a way to counterattack. Laguna suggests an idea that will take Edens Zero to the desert of Planet Sandra.

Shiki and Laguna's former companions prepare to launch an attack on Nero and try to stop Orc from placing the bombs on the planet.