HUMANITY’S LAST HOPEIt’s been seventeen long years since the Fleet of Fog―a mysterious, unmanned fleet of powerful vessels that appeared out of nowhere―took control of the oceans, barring humanity from traveling between continents or islands. During those years, people the world over have dreamed of a revolt that would let them take back the seas, but there’s been no hope―until now.A weapon powerful enough to damage the Fog’s vessels has finally been invented, and there’s just one way of getting the critical information and prototypes from Japan to America, where the weapon can produced! The submarine I-401, with its humanoid avatar―a “mental model” named Iona, who’s taken the shape of a young girl―was once part of the Fleet of Fog, but has chosen to side with humanity.Now captained by Chihaya Gunzo and his crew, the I-401 is the only ship under human control that can move freely through the seas. But she answers only to her captain, and he answers to no one.
HOME SWEET HOME?The I-401 and her intrepid crew, captained by Chihaya Gunzo, have escaped the trap set for them by the Fleet of Fog outside their home port of Yokosuka. Successfully returning home after two years away should be a triumphant occasion, but there are those who think otherwise. In fact, if they have their way, they will take the I-401―along with her mental model, Iona―away from Gunzo entirely and bring her back under government control.Human politicians aren’t the only players with rival factions. The ships of the Fleet of Fog have very different ideas about how to pursue the I-401, and what to do once they’ve located her. Worse, some are just as interested in Gunzo himself as they are in his ship!Yet all these forces have failed to reckon with Gunzo’s determination to control his own destiny, or with Iona’s willingness to join him wherever he leads!
Chihaya Gunzou, captain of the sentient submarine known as I-401, is renowned for his unorthodox tactics. His unpredictability is a strength when it’s just him and his crew against the world, but with two massive Fog battleships attacking their home port, Yokosuka, the I-401 has to team up with a human-built submarine to try to take them down—without letting the Fog ships anticipate their next move! The good news is that the other sub is a “White Whale,” representing the most cutting-edge technology Japan can produce. What’s more, Gunzou has an invaluable advantage: a former crew member is temporarily serving as part of the White Whale’s crew, and she knows how Gunzou thinks. Meanwhile, the Fog battleships Kirishima and Haruna are determined to be the ones to capture the renegade I-401, and they have a plan that no one can see coming.
ENEMY UNKNOWNThe Fog battleships Haruna and Kirishima have been destroyed through the combined efforts of the I-401 and the Japanese government’s “White Whale” sub, and the port of Yokosuka is safe-but the same can’t be said for the I-401. While still damaged from the battle, the 401 comes face to face with a Fog submarine that Iona doesn’t recognize, and it’s not exactly friendly!Back on land, Haruna, the mental model of the destroyed ship, is found by Osakabe Makie. The mental model and the precocious human child strike up an unlikely friendship, and Haruna learns that there’s far more to Makie than meets the eye.
THE UNLIKELIEST OF FRIENDSThe mansion where Professor Osakabe and Makie live is under attack, and nobody is happy about it: not the government, not the residents, and not even the attacking soldiers, who find themselves face to face with Haruna and learn firsthand that even without their battleships, the Fog’s mental models are a force to be reckoned with!Haruna’s world has been turned upside down since the I-401 destroyed her and Kirishima’s battleships. She’s learned that Osakabe Makie has also become her friend. And now Haruna is quickly learning the meaning of both “friendship” and “loss”-concepts she’s never had to grapple with before.
Alliances and subterfuge are the order of the day! Japan’s military, anxious to prevent the the sentient submarine 401 from leaving for the United States, takes desperate action. What they haven’t banked on is Gunzou and his crew getting help from two Fog ships: Hyuga, who’s kept the 401 in good repair and maintained the crew’s base of operations, and the opportunistic Takao, who’s allied herself with them in pursuit of her own goals. On the other side of the world, Gunzou’s father-the 401 ’s former captain, Chihaya Shouzou–supported by the Musashi and other likeminded Fog vessels, announces a new approach for making Earth’s oceans once again safe for humanity and Fog alike, but under his authority. Gunzou has plans of his own for bringing peace to the world, if only Japan can be persuaded to go along with them…
Having joined Gunzou and the 401’s side in the struggle between humanity and the Fog, Takao is eager to prove her worth—and her strength and experience are about to be put to the test! Remotely operating the fake “401” taken by Japan’s military is no small task, even for her, and the human-crewed U-boat 2501, captained by Zordan, is all too eager to take Takao down. Gunzou and his crew are faced with a painful decision: go to their new ally’s aid, or seize the opening to get their mission to the U.S. properly underway? But help comes from an unexpected source…
Takao was sailing and keeping a good distance from Dummy to assist Dummy’s safe arrival at the Army in Yokosuka, when he was suddenly attached by U-2501. 402, on a covert mission, saved Takao from this surprise attack. Meanwhile, Haruna, Maya, and Kirishima have gone to Hakodate, when Makie was rescued.
The battle between 401 and Kongou begins at last—but Gunzou and Hyuga are off on a mission of their own. Meanwhile, in Yokosuka, Takao goes undercover. Posing as a student at the National Maritime Institute of Technology where Gunzou and the 401 crew studied, Takao tries to uncover the true story behind Facility Number 4.
With the flagship Kongo unable to maneuver while in the midst of equipment prep, 401 successfully breaks through the picket established by Hiei and her “student council”–only to be drawn into a perilous conflict when enemy reinforcements appear out of the blue. Meanwhile, Gunzou has left to rendezvous with the White Whale, but while separated from 401, he comes under attack by a vessel from the Oriental Fleet. The tide of battle turns in Volume 10!
After a hard fight, I-401 is still operational–but just barely. With a gouge in her hull, her Super-Graviton Cannon annihilated, and her Wave-Force Armor out of commission, there doesn’t seem to be much hope. Gunzou’s got an idea–but will it be enough to get I-401 out of hot water? The final stage of the clash between Blue Steel and Kongou’s hunting fleet has begun!
In the fight against the Kongo, Iona’s mustering all the strength she can get–including Ashigara and Haguro, who are now stuck aboard the 401. With the Kongo on the hunt and nowhere else for them to go, the mental models have no choice but to lend their enemies a helping hand. The end of the battle between Kongou’s hunting fleet and the 1-401 draws nigh!
After a tough battle, the I-401 has managed to emerge victorious against the Kongo. But they’re not safe yet as enemy reinforcements are already on their way. With Gunzou still aboard another ship, Iona must make a tough choice: risk it all to save her captain, or make a quick getaway and save her crew…
Gunzou might still be missing in action, but Iona is determined to make sure that his plan to smuggle a warhead across the Pacific Ocean goes ahead. If it’s successful, it will give humanity a much needed win against the Fog. But in order for the plan to work, the I-401 will have to act as a decoy and go toe-to-toe against a dangerous enemy.
The Fog and humanity have been at war for decades, but only recently have the two sides started to try and understand each other. Several mental nodes have even enrolled in a human school, becoming students at the Maritime Academy of Technology. But are they there to work towards peace, or to better learn humanity’s weaknesses?
In recovery on Hashira Island, a resurrected Chihaya Gunzou meets the Siren, a mysterious figure who offers him a new perspective. Meanwhile, the White Whale’s journey slows to a crawl in order to avoid the Fleet of Fog. With their mission in jeopardy, Iona, Hibiki, and Komaki draw ever closer to their hour of reckoning.
Amidst the preparations for the National Maritime Institute of Technology’s school festival, Takao and 402 make their way into the heavily guarded “Facility Number Four.” Deep below the burned-out ruins of the facility lies a strange secret. Elsewhere, in order to protect the White Whale from an encroaching Fog patrol fleet, the crew of the I-401 creates a diversion, only to find themselves ambushed!
While protecting the White Whale from an approaching Fog patrol fleet, I-401 is ambushed by the Mutsu…but there’s something strange about the battleship’s tactics. Meanwhile, Takao, now tasked with guarding Facility Number Four, faces off against Haruna and Kirishima, who are desperate to discover the secrets within!
The National Maritime Institute of Technology’s school festival is in full swing! Beneath the hustle and bustle, Takao and Atago face off against Kirishima and Haruna, who are trying to break in to Facility Number Four. Meanwhile, on Hashira Island, Gunzou plots his escape!