Yuuji Sakai, the usually vacant and somewhat weak protagonist, lives an ordinary life until the sudden appearance of a monster disrupts his ordinary life. Under the setting sun, Yuuji is suddenly attacked by an alien monster that transforms human "existence" into spiritual fire and then devours it.

At this time, a girl who called herself "Flame-haired and Burning-eyed Slayer" appeared and rescued Yuuji from the monster's mouth. Yuuji Sakai named her Shana based on the name of her large sword.

She told Yuji that his life was about to end - it turned out that outside this world, there was another world called the "Red World". In order to realize their ambitions, the people there took away the world's original power, the "power of existence", from humans one after another, and Yuji was one of the victims.

After the Crimson Apostle took away the "Power of Existence",...

[Slightly hardcore] + [A huge number of self-created academies and students] + [With both angst and sweet moments] + [Daily life/battle]...

Thirty years ago, the Seventeenth Joint Campus was destroyed by an unknown force, turning the once prosperous academy into a desolate ruin. Our forefathers fought desperately during the catastrophe, sacrificing their lives to give their descendants a chance to survive. However, the survivors still wander among the ruins, lost, helpless, and uncertain of the future.

Just as despair was spreading, a firm voice rang out:

"Reconstruction, revival, revenge."

Guided by this brief yet powerful message, the students of Campus 17 wiped away their tears and rose again. They rebuilt their homes from the ruins, unearthing buried scientific discoveries from the depths of the rubble, etching the tragedy into their hearts and transforming past pain into motivation for progress. Beneath the wasteland lies not only a shattered civilization, but also revelations powerful enough to change the future.

Thirty years later, when a similar disaster struck another school known as "Children's Eden," the students of the Seventeenth Campus resolutely raised the blade of revenge. They were no longer helpless survivors, but fighters who had overcome the shadow of death. With thirty years of accumulated experience and the strength forged from the ruins, they would safeguard hope and reverse their fate.

"The past belongs to history, but we remember it."

"What is now ruins, we will rebuild."

"The future belongs to hope, and we create it."

[Slice of Life, Harem, Heartwarming, Funny] Louis, a little boy who fell from the sky. Ship girls, a group of lonely, infighting girls, but when the ship girls met Louis, the port already had a commander. As the only commander in the port, Louis's daily life is busy and bittersweet. The ship girls steal his clothes, rob him of his food, and even beat him up in alleyways. Every time, Louis gets sucked dry by the ship girls; anyone who doesn't know better would think they're vampires. "White Dragon, give me back my bitter tea!" "Frederick the Great, don't come any closer!" Today, Louis is still being driven crazy by the ship girls...