A 21 years old rebel and main protagonist in the OVA´s.
He ones belonged to the Blue fleet, but during his past he was implicated in the disappearance of his best friend Katsuma, since then he quitted and lives his life alone as a treasure hunter. Officer Mayumi Kino managed to convince him to return to the fleet after the place were he was living is attacked by a group of mecha known as Spiders, from the army of Zorndyke. They scape and get to the Blue N6, were he agrees to cooperate with the captain Iga and the rest of the crew. Wile they are talking the submarine is attacked by a Musca and some Spiders, and he gets, along with Mayumi, inside a grampus, a smaller battle ship, in order to repeal the enemy. The submarine manages to kill the Musca and Tetsu eliminates all the Spiders but one, that gets hit and disabled, but not completely destroyed. Tetsu then saves the female hybrid pilot of the enemy ship, Mutio, and she runs away. Ones they are back in the submarine, the hole crew starts a travels to their underwater base, there Commander Muranami explains the plan to end the war for ones at all, attack the main base of Zorndyke in the South Pole, and Tetsu discovers that his old friend Katsuma had been found, but it had been turned partially into a hybrid and its taken inside the Blue N6. The Ghost Ship attacks the Blue main base and the crew has to run away along with other naval ships. Tetsu tries to prevent the total destruction of their base by piloting a grampus by his own, but he gets hit and its forced to use his safety device. Later he is saved by Mutio and a kindhearted Musca. That Musca takes him back to the Blue N6, but the crew inside the submarine shoots him, believing he´s another enemy. Mayumi takes a grampus and saves Tetsu. Ones inside the submarine again he frees Katsuma and escapes along with Mayumi inside a grampus, in order to reach the enemies South Pole main base in an attemp to stop the war without the use off brute force. They get to the South Pole and manage to find Zorndyke. There he explains them the machine that modifies the earth´s magnetic fields is operated by his own heart, then Mayumi tries to kill him but Tetsu stops her, and Zorndyke says that the war will end ones his heart stops beating and his soon going to die, so its their choice to destroy the South Pole base or not, but the war will be over in any case. They call the Blue N6, that had been waiting for them for the final decision, and stop the South Pole operation. Tetsu and Mayumi wait for the crew to pick them up in the shore, wile the hybrids travel to the deepest regions of the ocean lead by the Sea Army´s commander, captain Verg.