Miho wanted to attend a school that didn’t offer Tankery and she thought she did. But when the student council gives her an offer she can’t refuse, her past comes to haunt her.
With 5 tanks found, the Tankery class split into teams and stage their first mock battle.
Mako, who is revealed to be a childhood friend of Saori, joins the others on the tank, which soon comes across a perilous bridge which Hana has trouble navigating. After a hit from enemy fire knocks Hana unconscious, Mako takes over as driver and manages to safely navigate to the middle of the bridge. There, they manage to find perfect cover from enemy fire whilst Yukari takes out the enemy tanks, securing victory for Miho's team. Whilst celebrating their victory, the team decides that Miho should be the commander, with the roles of radio operator, gunner, driver and loader assigned to Saori, Hana, Mako and Yukari respectively, before going shopping for things to make the tank more comfortable. Later, the students are informed of an upcoming friendly battle against St. Gloria's Girls Academy, of which Miho is assigned as the commander for the school's team.
Tank malfunctions, deserters, and trigger happy gunners. Miho will have her hands full if Oarai Academy is to survive their first match.
Miho's uneasiness about the tournament is worsened after a run in with her sister, Maho. Noticing Miho's worry, Yukari decides to infiltrate Saunders University High School to gather intel on their opponents for Miho to use as reference. As the others visit her house, Yukari's parents thank them for becoming her friends, as she didn't have any due to her tank obsession. The match against Saunders soon begins and the Rabbit team is soon put under pressure by Saunders' numbers. As Miho manages to get them to safety, she discovers that Saunders is using a radio interceptor balloon to eavesdrop on their communications. With this knowledge in hand, Miho manages to use this to their advantage in order to lay a trap for Saunders, managing to take out one of their tanks.
As Miho once again uses the radio interceptor to lure the rest of Saunders away, the Duck Team manage to find Alisa's tank and lures it into an ambush by the other Ooarai tanks. After learning the truth about the radio interception, Saunders' commander Kay sends an equal number of tanks to pursue Ooarai as they chase after Alisa, taking out both the Rabbit and Duck teams. Despite the grim situation, Miho calms her nerves and urges her teammates not to give up. Climbing up to the top of the ridge, the Anglerfish Team manage to take out Alisa's tank before they are taken out themselves, winning the match. After Kay commends Miho on her victory and takes her leave, Mako receives a call that her grandmother has been taken into hospital. Hearing about this, Maho allows Mako and Saori to take her helicopter back to Ooarai to see her.
Ooarai is doing well but the need to for additional tanks leads the group to searching the entire ship for new firepower.
Ooarai has gotten cocky with their recent victories and the upcoming match against Pravda will bring them back to earth.
The news of the school closure has hit the moral of the team hard. The offer of surrender is beginning to look more tempting as the hours creep on, but Nishizumi has other plans.
The final battle is coming up and students are approaching Nishizumi in hopes of joining Tankery. The Tankery club is on the lookout for new tanks.
Ōarai manages to escape Kuromorimine's ambush by using a smokescreen to conceal their retreat, where they take up defensive positions on top of a hill. A fierce battle begins, with Ōarai managing to disable several of Kuromorimine's tanks. Thanks to a distraction created by the Student Council, the Ōarai manages to retreat again while Kuromorimine stops to regroup. However, in order to reach their destination, Ōarai has to cross a deep river. Unfortunately, Rabbit Team's M3 Lee stalls in the river. Faced with leaving Rabbit Team behind or risk having Kuromorimine catch up to them, Miho is reminded of her previous finals match. However, the rest her crew encourages her to go and help Rabbit Team, much to her relief. Miho takes a rope and leaps across several of Ōarai's tanks in order to reach Rabbit Team, and the other tanks tow the Rabbit Team out of the river. They then make their way to a nearby town, destroying a bridge to force Kuromorimine to take the long way around.
Ōarai's team manages to defeat the Maus through a team effort, but Turtle Team's tank is damaged and disabled. The main Kuromorimine force descends on the town. In the fierce fighting, Ōarai's tanks are picked off, but Leopon's team blocks off a doorway, cutting off Miho and Maho's tanks from the rest of Black Forest's forces. A tank duel ensues between them, and Miho barely emerges victorious, winning the match in the process. The Ōarai crew and their fans celebrate their victory, ending with a parade through the town.