Episode 12

Synopsis
In the throne room of the Spiral King, General Cytomander mocks Guame's failure to execute Team Dai-Gurren. Guame retorts that Cytomander never leaves the capital at all, but the General of Air replies that he will set out when the Spiral King commands him to. Noting Adiane's absence, the Beastmen commanders realize that their fellow General is still trying to destroy the ones who killed Thymilph. Cytomander sneers at her stubborness, but Guame points out that with the ocean between the humans and Teppelin, fortune might be turning in Adiane's favor..

Heading straight for the enemy capital, the Dai-Gurren arrives at the ocean, and all the guys get excited at the thought of the girls wearing bathing suits. This causes Yoko to beat them all up for being lecherous, and she cites how their top priority is to head for the capital, so they don’t have time to play around. Leeron, however, points out that they have to cross over this ocean to get to their goal, and since the Dai-Gurren is made for use over land, he needs time to make it seaworthy. This means that they do indeed have time to play, and the men can’t wait to see Yoko and Nia in their swimsuits. Yoko’s amount of skin exposure disappoints them (causing a brief shouting match between herself and Kittan), but they soon go crazy for Nia. Yoko's anger is further stoked by the fact that Nia is superior to her in every beach game, from volleyball to suikawari (watermelon splitting) to making sand castles to seeing who can hold their breath the longest underwater. It also doesn’t help that when Nia brings Yoko a bowl of crab during the subsequent barbecue, Yoko accidentally drops it and gets laughed at by the men. She storms off in a huff, causing the boys to wonder if she lacks a sense of humor.

Meanwhile, Leeron finishes installing the equipment of the Dai-Gurren (mostly flippers and a paddle), so it’s time for them to head across the ocean. Although everything seems to proceed perfectly at first (despite Attenborough accidentally sending them flying across the water when they embark), they soon come under torpedo attack from Adiane’s flagship, Dai-Gunkai. The Dai-Gurren attempts to return fire, but it doesn’t score any direct hits with either its cannons or depth charges. As Adiane attacks the Dai-Gurren in her personal Gunman, Gimmy and Darry barely escape the ship's lower viewport before it is severed from the Dai-Gun. Fed up, Kittan heads out in his Gunman, but he quickly finds that it’s not suited for underwater combat when water starts pouring into the cockpit. The Gurren Lagann can still fight because its regenerative abilities allow it to self-seal, but Adiane’s Sayrune easily knocks it around, clearly superior below the waves.

Dai-Gunkai's acting commander, Viral, muses that he wanted to destroy Gurren Lagann himself, but will offer the honor to Adiane, as he has other matters to attend to. Under Viral's orders, the Dai-Gunkai clips the Dai-Gurren’s flippers before grabbing its hull and dragging it underwater. Simon and Rossiu are unable to help because they have their hands full with Adiane, and so the other guys panic when water starts pouring into the bridge. To their surprise, it is Nia who tells them to calm down - she feels that it’ll be okay because she trusts in Simon to come through for them.

With his friends going under, Simon finally becomes determined enough to put on his goggles and fully power up the Gurren Lagann. Transforming its arms into drills to free it from the Sayrune’s grasp, he then creates a huge drill on is head to allow it to propel its way back towards the surface, speeding upward faster than the Sayrune can catch it. In desperation, Adiane throws Sayrune's wings like a boomerang, but they simply shatter on contact with the drill. The force of the Gurren Lagann hitting the Dai-Gurren is enough to send it back above the water, ripping off Dai-Gunkai's arms in the process.

The battle is far from over, however; the Sayrune leaps out of the water and plunges its arm into the bridge of the Dai-Gurren. With Nia in her mecha's claws, Adiane warns the humans not to attack if they want to see the former Princess alive. Dai-Gunkai emerges and points its cannons at Gurren Lagann, but Adiane orders Viral to wait. Using her hostage as leverage, she orders Dai-Gurren to aim at Gurren Lagann, preparing to blow their own mecha to pieces. Dayakka is forced to comply, as no one is willing to risk hurting Nia.

Yoko, however, isn’t about to stand down just because Nia's been taken hostage. Standing in the hole left by Sayrune's attack, she draws her rifle and prepares to fire straight at the girl. As Adiane taunts her and her teammates gasp in horror, Yoko looks through her scope at Nia, who simply closes her eyes. Yoko’s first bullet manages to miss Nia’s head, though it goes through much of her hair. Team Dai-Gurren nearly dies of shock, Simon cries out to Yoko, and Adiane snidely asks the sniper where she'll shoot Nia next. However, Yoko sees her target, and her next shot rips through even more of Nia’s hair, but also hits the Sayrune’s shoulder, causing it to drop Nia. Fortunately, the free-falling girl is caught by Old Coco before she hits Dai-Gurren's deck.

With Adiane's leverage gone, Team Dai-Gurren turns its cannons on the Sayrune. Desperate, Adiane claims that firing at so close of a range would destroy them all, asking if they're really that stupid. Yoko simply replies, "I'm afraid we are", and Attenborough wholeheartedly agrees, blasting Adiane with a point-blank salvo from Dai-Gurren's cannons. Horrified, Viral sends the Dai-Gunkai lunging at the other Dai-Gun, but Simon uses the Gurren Lagann to drill straight through the serpentine Gunmen. As Dai-Gunkai falls apart and explodes, Adiane whispers an apology to Thymilph before her own Gunman detonates. The subsequent explosion-rivaling a nuclear blast-creates a huge wave that the Dai-Gurren rides to the other side of the ocean, with everyone cheering the victory.

Elsewhere, on a lonely beach dotted with the wreckage of Dai-Gunkai, a ragged, despondent, and furious Viral punches the ground, cursing Gurren Lagann and Team Dai-Gurren.

In the aftermath, Nia approaches Yoko with a request: to trim and even out her now-tattered hair. As she cuts, Yoko asks Nia why she closed her eyes when Yoko was about to fire at her in the earlier battle. Nia’s response is that Yoko is a rifle expert, so she trusted her. At that, Yoko calls herself an idiot and apologizes to Nia for being suspicious of her. Yoko eventually finishes cutting Nia’s hair to a shorter style that both girls are happy with, and Nia immediately runs off to show Simon.

Major Events

 * Death of Adiane.
 * Nia gains Yoko's trust and respect, with the two becoming friends.
 * Nia's hair is cut short after it is damaged by Yoko's rifle shots.
 * Dai-Gurren crosses the ocean on its way to Teppelin.

Trivia

 * With her new short hairstyle, Nia looks a lot like Eureka from Eureka Seven.
 * When Sayrune destroys the lower turret of Dai-Gurren, every male crewmember except Leeron grabs their groin in apparent pain. This is possibly due to an increase in cabin pressure caused by the water flooding the underside of the ship.
 * Since the Dai-Gurren mecha looks humanoid, the underside represented the male groin and since it got blown up, every male crewmember imagined the pain and thus grabbed their own groin in response. It is a joke-reference that is used in comedy.
 * At the end of the episode when it shows Viral, he can be seen crying in his anguish. This displays Viral's secret crush on Adiane which becomes further supported in the manga.