The gate to an unknown world opens in Mikado City, which faces malicious invaders called Neighbors. An agency called Border responds to the attack.
Border agents hurry to the site of a Neighbor attack, only to find it in ruins. Meanwhile, Osamu tries to size up Yuma, a self-proclaimed Neighbor.
Trion soldiers enter through an irregular gate that opens at Osamuโs school. Wanting to protect his peers, he charges recklessly towards the Marmod.
Osamu reluctantly takes credit for defeating the Marmod to cover for Yuma, but is then chewed out for unauthorized use of a Trigger in real combat.
Kitora gallantly takes on an unknown Trion soldier dubbed the Ilgar, but is thwarted when it goes into self-destruct mode and heads toward the city.
While S-Rank member Jin investigates the cause of the irregular gates, Yuma follows the advice of his guardian Replica and does his own digging.
Osamu reveals that Chika attracts Neighbors. Yuma further explains the reasons why the Neighbors come to Earth and why they target certain people.
The Miwa Unit launches a brute attack on Yuma. Worried for his friend, Osamu is perplexed by Replicaโs explanation of why Yuma refuses to fight back.
Borderโs brass is split on what to do when Yumaโs Black Trigger obliterates the Miwa Unit. The truth behind Yuma and his father is gradually revealed.
Jin makes a surprising offer to Yuma and invites him to visit Borderโs Tamakoma Branch. He accepts on one condition-- that Osamu and Chika also come.
As the team learns of Yumaโs reasons for coming to Earth, Chika resolves to join Border to travel to the Neighborsโ world and find her brother.
New Tamakoma Branch members Osamu, Yuma, and Chika pledge to rise up to A-Rank, which requires them to vigorously train for intra-agency Rank Battles.
Concerned over the concentration of power at Tamakoma Branch, Borderโs high commander Kido orders his elite agents to seize Yumaโs Black Trigger.
Tachikawaโs elite unit closes in on Yuma, but Jin foils them. Just as another agent proposes an attack on Tamakoma, Jinโs Black Trigger is activated.
The power of Jinโs Black Trigger is unsheathed. As the battle between Jin and Tachikawa intensifies, other units arrive on site, adding to the heat.
With the help of the Arashiyama Unit, Jin defeats the elite units. When news of this ripples across Headquarters, Jin approaches Kido with a proposal.
On the day of Yuma and Chikaโs official induction into Border, Osamu is suddenly challenged by A-Rank #3 leader Kazama to a mock battle.
Osamu is astounded by the vast difference in his and Kazamaโs skill during the mock battle, but Kazama says something that sparks a fire within Osamu.
Rumored as having fought an A-Rank agent to a draw, Osamu is left perturbed. To his further surprise, he is challenged to a 10-round Rank Battle.
The 10-round battle between Yuma and Midorikawa commences. Kido calls Yuma to a defense meeting to discuss a predicted large-scale Neighbor invasion.
Border prepares for invasion based on Replicaโs info on the Neighborhood, the world of Neighbors. Sensing Osamu is in danger, Jin seeks Miwaโs help.
Border has the advantage at the outbreak of the Large-Scale Invasion, only to be blindsided by a new Trion soldier model called the Rabbit.
Border scrambles to deal with the Rabbits. Osamu and Yuma join in combat to protect the City, but Yuma is mistaken for an enemy and shot by snipers.
The massive number of Trion soldiers compels Border to scatter its forces. Chika is attacked by Trion soldiers while leading residents to shelter.
Border discovers Aftokratorโs true targets are C-Rank agents. Hyrein sends in humanoid Neighbors Enedra and Lamvanein to divide Borderโs forces.
The horned humanoid Neighbors overwhelm Border agents with tremendous power. Meanwhile, the Kazama Unit fights Enedra using Kikuchiharaโs Side Effect.
As Tamakoma-1 takes on humanoid Neighbors Hyuse and Viza in the city, a joint force consisting of top Border teams goes head to head with Lamvanein.
Kizaki discovers the secret of Hyuseโs Trigger and orders Karasuma and the others to retreat. Meanwhile, Enedra infiltrates Border Headquarters.
Viza and Hyuse go after Chika. As Yuma and Jin wage fierce battles, Osamu and Karasuma set out for Border Headquarters to evacuate the C-Rank agents.
Border manages to entrap Enedra, enabling them to go on an all-out counteroffensive. Meanwhile, a horde of Rabbits stop Osamu in his tracks.
Chika is cubified by Hyreinโs attack. Osamu castigates himself for his mistake, but soon recovers with his comradesโ help and sets out to save Chika.
Borderโs general manager Shinoda struggles to subdue the entrapped Enedra as he fights back with tremendous power using his Black Trigger.
In an effort to buy time until Osamu reaches Headquarters, Karasuma activates his Geist, which holds tremendous power as well as terrible risk.
Miwa more than holds his own against Hyrein. In the final stage of his battle with Viza, Yuma remembers his late fatherโs last words of wisdom.
A turn of events shifts the tide in the enemyโs favor. But just as Hyrein closes in on Osamu, Yuma and Miwa unleash a powerful blow against Hyrein.
The Large-Scale Invasion has been repelled, but not without consequences. In a comatose state, Osamu recalls Chika and his reasons for joining Border.
A week after Osamu wakes from his coma, he is met by high-ranking Border member Karasawa, who takes him to a press conference regarding the invasion.
An injured Osamu shows up at a press conference about the damage wrought in the recent invasion. He gives the media his frank and confident thoughts.
After Tamakoma-2โs striking victorious B-Rank Battle debut, Osamu tries to strategize for the next match, but suffers from paralysis by analysis.
Round 2 of the B-Rank Battle begins. A recovered Osamu is back with the team. Given the right to pick the stage, Osamu chooses a hilly neighborhood.
The Arafune Unit and its snipers are gradually cornered in battle. Arafune pulls out an Attacker Trigger to defeat Yuma, a move which surprises all.
Tamakoma-2 will face Suzunari-1 and the Nasu Unit in the next round. Meanwhile, Yuma challenges agent Murakami from Suzunari-1 to a solo Rank Battle.
Tamakoma-2 searches for a strategy to counter Murakamiโs Side Effect. Soon, the three battling teams plunge into a tumultuous match in Round 3.
As the teams battle under stormy conditions, the Nasu agents steadily launch their attacks as planned. Just then, Chikaโs trigger Ibis tips the scale.
The battle intensifies when Chikaโs actions split the agents up, resulting in a fierce three-way Attacker fight among Yuma, Murakami and Kumagai.
Suzunari-1โs Murakami and Tamakoma-2โs Yuma clash on the west side, the two ace Attackers giving it their all to earn victory for their teams.
Round 3 comes to a conclusion after a hard-fought battle. During the post-battle commentary, someone points out Tamakoma-2โs fatal weakness.
Tamakoma-2 rises to the upper B-Rank. As they prepare for battle with the top B-rank teams, Osamu is tormented by his inability to contribute.
Jin and team must fend off a band of unknown Trion soldiers attacking Mikado City. Meanwhile, a pair of mysterious children show up at Tamakoma-2.
When Osamu discovers Xeno and Lilith are fugitives from the Errant Nation Ergates, he takes them back with him, but an invisible attacker stalks them.
Amidst the onslaught of Trion soldiers, Osamu and crew forge a bond with Xeno and Lilith. Xeno offers information in exchange for a duel with Osamu.
Chika and the others come up with a plan to cheer up lonely girl Lilith, but little do they know Neighbors Charon and Giev are hot on their heels.
When Miwa and team visit a high-rise outside Mikado City, spider-like Trion soldiers attack the area, trapping the citizens inside the building.
Xenoโs attitude towards Yuma and Chika upsets Osamu. Meanwhile, the team must join forces with Kitora in response to attacks by a giant Trion soldier.
Borderโs elite agents assemble to wipe out Gievโs Trion soldiers, but are unable to impede Giev as he carries out his plans to blow up Shizuka City.
Osamu and crew enjoy a day of fun, but Giev unleashes a powerful Trion soldier on them. To save the team, Lilith undergoes a shocking transformation.
Lilith reveals her true powers. Giev and Charon flee, but take Osamu with them. The story behind Xeno and Lilith is finally explained.
Yuma, Chika and Xeno rush to save Osamu, but fall prey to Gievโs cunning trap. Separated from the others, Yuma finds himself cornered in an odd place.
Yuma battles Giev. Gievโs fierce attacks with his Black Trigger and skillfully coordinated moves with Charon make the fight tough for Yuma.
Yotaro from Tamakoma tries to catch up with Konami and the others but meets a girl named Kokoa instead. Meanwhile, Border agents fight Trion soldiers.
Giev and Charon launch a desperate attack on Tamakoma-1. With just one day until Xeno and Lilithโs departure, Yuma and the others must protect them.
As Shizuka Cityโs residents are held hostage by Charonโs plan, the surprising truth about Giev is revealed. A-Rank agents gather for a final showdown.
Unable to fully trust the team even under dire circumstances, Xeno heads out to rescue Lilith alone, the destiny of an ill-fated future in his hands.
Yuma and team bid farewell to the fugitive Xeno and return to Tamakoma to prepare for their rank battle. Meanwhile, Hyuse is taken to Headquarters.
A transformed Enedra reveals the truth behind the Large-Scale Invasion and attack on Chika. B-Rank #1 Unit leader Ninomiya visits Tamakoma.
As members of Tamakoma-2 train for their battle with the upper B-Rank teams, Yuma encounters Kageura, the violent leader of the B-Rank #2 Unit.
Yuma faces Kageura and immediately realizes how astoundingly skilled he is. Osamu gains some newfound confidence from his training as a shooter.
Tamakoma-2 fights Ninomiya, Kageura and Azuma Units in the B-Rank top team battle. As tensions rapidly rise, Osamuโs opponents gang up on him.
In midst of a fierce battle, Chika struggles to overcome her weakness, but inadvertently reveals her location. Yuma takes on multiple Attackers alone.
As Kageura challenges Yuma to an ultimate Attacker battle, Ninomiya takes advantage of the situation. After the battle, Osamu makes a grave decision.
While Borderโs top teams grapple with news of an imminent attack by another Planet Nation, Osamu seeks out an ideal candidate to bolster Tamakoma-2.
Osamuโs unit strives to push their envelope. Chika receives helpful advice on overcoming her weakness, while Yuma is recruited by an A-Rank leader.
Osamu seeks guidance from Kitora to reach his goal. As Border agents engage the invaders, Yuma and crew enter the B-Rank Battle with renewed resolve.
An expedition force from Galopoula forms a plan to attack Border Headquarters. When Jin predicts the assault, the squads mobilize to defend the base.
The Galopoula team continues its mission to reach the expedition ship. Just when Rei learns how to defeat the Dogs, smoke obscures her vision.
While Kuroe and Kitora engage with Yomi's Idra, Kumagai and Rei continue fighting Wen So, who confuses them by splitting into multiple clones.
Tachikawa and Konami fight to prevent Gatlin from firing his cannon. Meanwhile, Hyuse asks Reghindetz for assistance in returning to Aftokrator.
The Border agents prepare for the next round of the B-Rank Battle. Tamakoma-2 sizes up its opponents: the Katori and Kakizaki squads.
Chika keeps the Katori and Kakizaki squads pinned down with her powerful shots. As the two units push back, Yuma and Osamu move in to confront them.
Yuma uses an unconventional method to survive Kakizakiโs last-ditch attack. After her squad flanks Osamu, Katori taunts him with a question.
After the battle, the commentators analyze the action and the various squads' performances. Later, Yotaro gives Tamakoma-2 some news about Hyuse.
Tamakoma-2 meets with Border officials to convince them to let Hyuse join the unit. Kido agrees to Osamuโs proposal โ but on one condition.
Ahead of the next B-Rank Battle, the Tamakoma-2 and Oji squads formulate their strategies. Hyuse's enlistment into Border causes a stir.
Ikoma's long-range whirlwind attack forces Yuma to retreat, but Oji releases his Hound in pursuit. Mizukami responds by going after Ojiโs squad.
While Oki prevents Chika from sniping, Ikoma slices through the surrounding houses. Oji attacks Yuma as the buildings collapse around them.
With Hyuse now a part of the Mikumo Squad, Tamakoma-2 welcomes back two senior members. Later, Osamu learns more about the Tamakoma Branch's past.
Kageura invites some of the guys to his family's restaurant, where he reveals that Yuzuru intends to throw the next match due to his crush on Chika.
For Round 7, Suzunari-1 selects a cityscape with a large shopping mall. The participating squads form their strategies with an indoor fight in mind.
The Gunners of Suzunari-1 pin down Kageura with their constant fire. As Osamu tries to close in on Yuzuru, the lights in the entire mall turn off.
After alerting Osamu to a change of plan, Hyuse summons defensive barriers to provide cover for himself and Yuma as they approach Kuruma and Murakami.
With just two squads left in Round 7, the members of Tamakoma-2 must choose between searching for their remaining opponents or protecting Chika.
Gossip spreads among the C-Rankers about Tamakoma-2's newest member. Hoping to quash the rumor, Osamu visits the Border public relations department.
Osamu and his unit end up sharing a meal with their next opponents, who hint that they have figured out Tamakoma-2's strategy for the next round.
Hoping to gather intel before the final round, Yuma arranges to meet Yuba Squad leader Takuma. First, he and Osamu speak with one of Takumaโs mentees.
Tamakoma-2 discusses what it has learned about its upcoming opponents. Taking Chika's decision into account, the squad begins formulating a strategy.
The squads review their tactics before the final round begins. The fight gets off to an explosive start when bombs rain down on the battlefield.
Surrounded by foes, Hyuse requests that Chika fire a powerful Trigger on his position, but Tonooka's bullet causes it to explode directly above her.
With Tamakoma-2's key player out, the other units continue the frenetic fight. As Osamu and Yuma head toward their target, Tonooka takes aim at Chika.
Ninomiya Squad stands out in the open and waits for the Tamakoma-2 members to reveal themselves. Osamu, Yuma and Chika spread out before attacking.