Author's note- As far as I can tell no one has done something like this yet, and I am surprised I will be the first. If I am not please let me know. Also FYI I have only seen the anime and read stuff on the English wiki.

Prologue

December 21, 2012 is the day everything changed, heralded by Lake Toba attempting to give a repeat performance of the catastrophe 75,000 years ago. Thankfully for the human race the blast was only a level seven event on the volcanic eruption index, however this did little to bring comfort to the people of South East Asia. Modern civilization on Northern Sumatra ceased to exist, tsunami's destroyed coastal settlements along the Bay of Bengal. Asia was not the only continent besieged by extreme conditions simply the worst hit. A massive hurricane tore through the Caribbean Islands, Europe was engulfed in blizzards, while solar flares buffeted the many satellites orbiting the planet. By the end of the first day one billion were killed, missing, or injured, with damages in the trillions of dollars.

Yet despite being dealt a heavy blow, humanity continued to survive, highlighting the best that mankind has to offer. Aid quickly flooded into the areas ravaged by Mother Nature as slowly abated. It was into this chaos that they arrived, rising from the deepest depths of the ocean, like the Kraken of old. Spreading slowly as if guided by some unseen intelligence these monsters began destroying anything manmade that sat above or below the water. Initially over looked as the ravings of desperate refugees, their presence wasn't recognized until several super tankers went missing after clearing the Persian Gulf. There oily remains littering the Indian Ocean. Within a month nearly a third of all large commercial vessels were at the bottom of the ocean as international trade ground to a halt. In order to keep the global economy running the British and Americans reinstituted the convoy system that served them so well in the Second World War. The mission was an unprecedented disaster as 50% of the ships were sent to the bottom by dark humanoid creatures.

Kraken, Chuthulu, Leviathan, many names were used to describe the dark beings rising from the abyss. However Abyssal was the name that was eventually chosen after a second convoy, a show of force by NATO was completely destroyed. Despite the firepower wielded by the modern navies of the world, they were powerless to stop these alien beings. Modern weapons were still highly effective against the Abyssals, when they were able to connect. The fog created by the Abyssal flagships distorted radio and other waves rendering guided munitions obsolete. In the off chance that the weapon did connect, the Abyssals possessed remarkable rates of healing, shrugging off all but the most violent of attacks.

Forced to cede the oceans of the world to these mysterious beings, humanity adapted countries focusing inward forced to deal with their own problems, unable to help, friends and family across the far flung oceans. The United States, Canada, and Mexico began making moves to increase the already close socioeconomic ties they shared. The nations of Europe grew closer out of necessity due to a lack of trade. Russia grew in importance as the best option for shipping goods between Europe and Asia. China was rife with internal strife compounded by a flood of -refugees from South East Asia. Japan was hit the hardest lacking the land and resources to retain a truly modern society without the benefit of international trade.

Necessity is the mother of invention, and when the second Abyssal assault began it was Japan, a tiny nation that all had written off, who was ready for the invaders. Kanmusu or ship girls as they quickly became known by, turned back an Abyssal assault on Tokyo bay. If the abyssals are the embodiment of the fears, and regrets of all those lost at sea then the ship girls are their mirror image. Ships reborn into human form driven by the hopes and dreams of those who were lost at sea. Taking human form but retaining all that made them deadly combatants, the ship girls took to the sea with a vengeance determined to protect their home. Powered by an unknown force many referred to as magic their weapons were more than capable of destroying abyssals and preventing their regeneration.

Word quickly spread to the nations of the world, as they to summon their own ship girl forces. Catching the Abyssals by surprise, the ship girls quickly pushed the Abyssals out of the rivers and coastal waterways, before a new stalemate was reached. Looking to increase their forces, the major nations of the world quickly found a quirk in the construction or summoning of their ship girls. No ship laid down after World War Two was able to be summoned. Some thought this to be a failsafe embedded in the process by the Japanese. Others however believed it had to do with a lack of conflict needed to create the bonds between men and ship since the Second World War. Either way the world now had hope that the abyssals could be defeated, sent back to the abyss from whence they came.

Author's note- I know it seems a bit dark, but that was just to set up the overall universe. I promise the story is going to be more action and light hearted fun for the most part