Snowball Earth - Season 1

In 2025 AD, after a sudden invasion of intergalactic kaiju, a painfully shy boy, Tetsuo Yabusame, saves the autonomous bomb Yukio and becomes an unlikely defender of Earth. Ten years later, now hailed as a "savior", Tetsuo heads into space with Yukio for the Final Battle. With 20,000 kaiju closing in, humanity's fate is on the line to bring an end to this relentless conflict!

The world outside the escape pod is covered in snow and ice, and devoid of life. Tetsuo sets off to find human survivors, his promise to Yukio on his mind. Riding an excavator that he finds in the ruins, he battles an intergalactic kaiju that attacks him, and it is then that he encounters the members of humankind who've survived! Can Tetsuo finally make the "friends" that he's always longed for?

Tetsuo is gradually accepted by Ao and the others he meets on the frozen Earth. However, his peace is short-lived, as he is attacked by a galactic monster unlike any he has ever fought before. As people flee in unison, Tetsuo stands alone against the monster. He finds himself in a desperate situation against its overwhelming power, but just when all hope seems lost, who should appear—!

Tetsuo and Yukio cross the snowfields and head towards Ao's base, "Mishima Mall." Tetsuo receives a warm welcome from the survivors as a "savior," and through his interactions with Ao and Takimura, he experiences the warmth of civilization and human connection he hasn't felt in a long time. But why is this place the only warm place in this freezing world? The secret of "a certain entity" that saved the mall is about to be revealed!

Welcomed into the Takimura family, Tetsuo meets Hagane, a girl who lost her mother a month ago. She shows Tetsuo "something" that her mother made in her workshop. Meanwhile, an organization called "E-RDE's Light (Vierde)," led by a mysterious man known as the Colonel, learns of Tetsuo's survival and begins to make ominous moves. The shadow of a new enemy is quietly closing in on Mishima Mall!

Suddenly, Yukio is attacked by snipers from afar. The group that appears is "E-RDE's Light (Vierde)," a unit of boys and girls who control monsters. Their commander, Sagami, was once a member of "E-RDE (Erde)" just like Tetsuo, and is a man consumed by a twisted sense of justice and intense jealousy. As past grudges and madness intertwine, Tetsuo and his friends are subjected to a relentless attack!

The half-destroyed Yukio is under heavy attack from the mighty monster "Hercules," the Commander's Sword, which emerges from the snow. Tetsuo desperately tries to defend himself, but he is gradually cornered by the enemy's overwhelming power and calculated tactics. In this desperate situation, the measure Tetsuo takes to turn the tide of the battle is... communication for the first time!

As Tetsuo and his friends rush back to the mall, they receive a communication from an unknown source. At that moment, Mishima Mall is under attack by the "E-RDE Light (Vierde)"! A full-scale battle ensues as the village chief activates a secret "anti-kaiju defense system" to fend off the kaiju's onslaught! Can the residents hold out until the "savior" arrives?!

As Mall is forced into a defensive position, Ao returns, consumed by rage, and together with the "Human Land," confronts the enemy. Surrounded by monster tamers from "E-RDE's Light (Vierde)," Ao skillfully manipulates the terrain and fire to outmaneuver his enemies. Meanwhile, the village chief, who was once a member of "E-RDE (Erde)," reveals Sagami's past!

With the help of the residents, Yukio's repairs are complete, and he returns to the battlefield as "Snowball Rampart," with an enhanced right arm! The rematch against his arch-nemesis, Hercules, begins. With Sagami seeing through all of Tetsuo and his allies' attacks, they search for a way to turn the tables! The battle between "Mishima Mall" and "E-RDE's Light (Vierde)" reaches its climax!

After a fierce battle, Tetsuo defeats Hercules. As the residents of Mishima Mall rejoice, Tetsuo attempts to speak with Sagami once again. Defeated, Sagami, in a dazed state of mind, reveals his past, his jealousy of Tetsuo, and his obsession with the "savior." What shocking truth will be revealed then?!

Touched by Tetsuo's pure feelings, Sagami begins to lose his will to fight. Yuma rushes to the scene, strongly rejecting Sagami's self-deprecating attitude and shouting out her feelings for him. Then, the tragic past of Sagami and the "E-RDE's Light (Vierde)" who survived the despair of the Great Freeze is revealed. What did they find at the end of the deadly blizzard?!

The avalanche that was controlling Sagami was actually a clone of the Humanoid, the culprit that caused the global freeze and led to the destruction of Earth! Shocked by this revelation, Sagami finds himself in a desperate situation, but Tetsuo and Yukio rise up as saviors. The avalanche attacks, now merged with the corpse of Hercules. With their bodies battered and bruised, the battle against their strongest enemy begins!