Daisuke Ashihara: 19 books

Earth is under constant threat from Neighbors, invincible monsters from another dimension that destroy our way of life. At least we have the elite warriors of Border, who co-opt alien technology to fight back! Our hero Osamu Mikumo may not be the best agent, but he’ll do whatever it takes...

Earth is under constant threat from Neighbors, invincible monsters from another dimension that destroy our way of life. At least we have the elite warriors of Border, who co-opt alien technology to fight back! Our hero Osamu Mikumo may not be the best agent, but along with his Neighbor friend Yuma,...

Yuma's Neighbor identity revealed, the Tamakoma branch safeguards Yuma, Osamu and Chika by recruiting them to their group of powerhouses and eccentrics. But Border headquarters wants Yuma’s Black Trigger badly enough to send agents from its top three squads to steal it!

Should Border admit a Neighbor into its ranks? Jin and Arashiyama Squad think so, and they clash against headquarters’ top agents to preserve Yuma’s right to enlist. After a brutal fight against his friends and peers, Jin makes an unimaginable sacrifice to put an end to the hostility and protect Yuma’s future at Border.

Border headquarters is abuzz with gossip about talented new rookies Yuma and Chika. But it’s Osamu who attracts the most attention when an A-Rank agent challenges him to a duel. Then it’s Yuma’s turn to fight when another A-Rank agent challenges him! Plus there’s that meeting with Border’s...

It’s a Neighbor invasion! Trion soldiers swarm Mikado City, wreaking havoc and capturing isolated Border agents. When the sinister humanoid Neighbors orchestrating the attack target Chika for her massive Trion, Osamu may be the only one who can save her! But can a B-Rank agent compete against the surprising power of this new alien foe?

Humanoid Neighbors from another dimension enter the battlefield for the first time! With strange Triggers that defy explanation, they make quick work of even top Border agents until the agents start to fight smart. Can Border turn the tide of battle in time to save Mikado City?

As the Neighbor invasion continues, Osamu’s brave defense of Chika lands him in combat against the Neighbor commander! Border’s weakest agent will have to do better than his best to win against a Trigger that seems to generate life itself.

With less than 16 minutes left until the crossroads Jin predicted, the endgame looms. Will Osamu make it back to HQ in time to save the cubified Chika?

With only seven seconds left until the crossroads, time is running out. Black Triggers face off as Miwa activates Fujin to bring the invasion to an end. But can everyone really escape the worst possible future?

After the recent Neighbor invasion, thirty-two agents went missing and Osamu, Yuma and Chika, a.k.a. Tamakoma-2 Squad, intend to go get those people back. But first they need to rank up through the Rank Wars. Having won their first match, they must now prepare to face off against Arafune and Suwa squads in the middle B-Rank Wars.

Having defeated Arafune and Suwa squads in the Rank Wars, Tamakoma-2 settles nicely into the middle B-Rank group. Their next match is against the infamous Suzunari-1 and the all-female Nasu Squad, both of which have their own ace Attackers! Can Tamakoma-2 overcome this challenge and fight its way into the top group without getting washed away by the tide?

Having fought their way into the top B-Rank group, Tamakoma-2 gets to battle it out with the big boys for a chance to make A-Rank. Can this squad of rookies win against seasoned veterans who are nicknamed the "A-Rank Reserves"? 

After being crushed in their last Rank Wars match and Jin refusing Osamu's request to join their squad, Tamakoma-2 is at a loss. Osamu is determined to learn how to fight with his team using his limited Trion and gets help from an unexpected source. But with a prediction of another invasion looming overhead, training may have to wait.