Story Arcs

World Trigger's Story Arcs

Border Saga

Introduction Arc

Introduction arc
Yūma Kuga transfers to Mikado City's third junior high school, where he meets Osamu Mikumo. Yūma learns of Border and the Neighbor invasions, and reveals that he himself is a Neighbor.
Manga		Anime
Number of Chapters	16	Number of Episodes	8
Osamu Mikumo Yūma Kuga Yūma Kuga 2 Osamu Mikumo 2 Yūma Kuga 3 Arashiyama Unit Ai Kitora Ai Kitora 2 Ai Kitora 3 Border's Upper Echelons Yūichi Jin Chika Amatori Chika Amatori 2 Miwa Unit Miwa Unit 2 Miwa Unit 3		A Visitor from a Parallel Universe Neighbors and Trion Warriors Osamu Mikumo's Talent A-Rank No. 5: Ai Kitora of Arashiyama Unit Talented Elite: Yūichi Jin Chika Amatori's Side Effect Miwa Unit's Attack Black Trigger

Black Trigger Capture Arc

Black Trigger Capture Arc
Yūma's identity as a Neighbor is outed to Border, who sends their best units to assassinate him and take his Black Trigger. However, he was recruited into Tamakoma Branch by Yūichi Jin, who joins force with Arashiyama Unit to protect his new junior.
Manga		Anime
Number of Chapters	16	Number of Episodes	8
Yūichi Jin 2 Yūgo Kuga Tamakoma Branch Yūma Kuga 4 Osamu Mikumo 3 Tamakoma Branch 2 Tamakoma Branch 3 Headquarters' Top Teams Yūichi Jin 3 Arashiyama Unit 2 Kei Tachikawa Yūichi Jin 4 Arashiyama Unit 3 Arashiyama Unit 4 Yūichi Jin 5 Yūichi Jin 6		The Organization Known as Border Tamakoma Branch Each One's Determination Tamakoma's A-Rank Members Border's Top Teams No. 1 Attacker: Kei Tachikawa Black Trigger: Fūjin The Future Advances

Border Enlistment Arc

Border Enlistment Arc
On Border's Official Enlistment Day, Yūma and Chika Amatori finally make their debuts, while Osamu battles Sōya Kazama, calling attention to their group. Later, Osamu and Yūma battle Shun Midorikawa, and are afterwards called to a meeting regarding an upcoming invasion.
Manga		Anime
Number of Chapters	11	Number of Episodes	5
Yūma Kuga 5 Chika Amatori 3 Osamu Mikumo 4 Osamu Mikumo 5 Osamu Mikumo 6 Yūma Kuga 6 Yūma Kuga 7 Yūma Kuga 8 Replica Replica 2 Yūichi Jin 7		Official Border Enlistment Osamu Mikumo vs. Sōya Kazama Rank Battle! Shun Midorikawa's Plan Clash! Yūma vs. Midorikawa The Neighbor World

Large-Scale Invasion Arc

Large-Scale Invasion Arc
A group of humanoid Neighbors, later identified as being from Aftokrator, invade Mikado City in search of Trigger users. Based on Jin's predictions, Border fights to protect civilians and C-rank trainees.
Manga		Anime
Number of Chapters	42	Number of Episodes	16
Large-Scale Invasion Large-Scale Invasion 2 Large-Scale Invasion 3 Large-Scale Invasion 4 Large-Scale Invasion 5 Large-Scale Invasion 6 Osamu Mikumo 7 Ai Kitora 4 Chika Amatori 4 Tamakoma First Aftokrator Tamakoma First 2 Kazama Unit Large-Scale Invasion 7 Large-Scale Invasion 8 Large-Scale Invasion 9 Large-Scale Invasion 10 Large-Scale Invasion 11 Aftokrator 2 Large-Scale Invasion 12 Large-Scale Invasion 13 Large-Scale Invasion 14 Large-Scale Invasion 15 Large-Scale Invasion 16 Aftokrator 3 Osamu Mikumo 8 Large-Scale Invasion 17 Large-Scale Invasion 18 Large-Scale Invasion 19 Large-Scale Invasion 20 Kyōsuke Karasuma Large-Scale Invasion 21 Shūji Miwa Large-Scale Invasion 22 Yūma Kuga 9 Large-Scale Invasion 23 Replica 3 Large-Scale Invasion 24 Osamu Mikumo 9 Yūma Kuga 10 Osamu Mikumo 10 Osamu Mikumo 11		The Large-Scale Invasion Begins The Divine Country, Aftokrator Miden's Chicks Border's Strongest Unit Fierce Fight! Enedra vs. Kazama Unit Border on the Counterattack The Organon User Crossroad of Fate Enemy General Hairein Osamu Mikumo's Determination Implacable Enedra Hairein's Terror Fierce Combat! The Battle of the Best The End of the Battle The Have-Not Hero and Partner

B-Rank Rank Battles Arc

B-Rank Rank Battles Arc
After the invasion, Yūma and Chika officially become B-rank agents, and form Tamakoma Second with Osamu as the captain and Shiori Usami as the operator. The unit joins the rank battles in order to become one of the top two B-rank teams and join the Expedition Force. Meanwhile, Border's A-rank units and free B-rank units thwart an expedition from Galopoula and Rodochroun to destroy Border's Expedition Ship. Out of necessity for the team, Hyuse joins Tamakoma Second.
Manga		Anime
Number of Chapters	114	Number of Episodes	21
Tamakoma Second Tamakoma Second 2 Tamakoma Second 3 Tamakoma Second 4 Tamakoma Second 5 Tamakoma Second 6 Shiori Usami Kō Murakami Yūma Kuga 11 Suzunari First Nasu Unit Nasu Unit 2 Nasu Unit 3 Nasu Unit 4 Kō Murakami 2 Yūma Kuga 12 Rei Nasu Tamakoma Second 7 Tamakoma Second 8 Aftokrator 4 Masataka Ninomiya Osamu Mikumo 12 Yuzuru Ema Masato Kageura Haruaki Azuma Yūichi Jin 8 Haruaki Azuma 2 Kageura Unit Masataka Ninomiya 2 Osamu Mikumo 13 Yūichi Jin 9 Yōtarō Rindō Chika Amatori 5 Aftokrator 5 Aftokrator 6 Galopoula Ai Kitora 5 Galopoula 2 Galopoula 3 Galopoula 4 Galopoula 5 Galopoula 6 Galopoula 7 Galopoula 8 Galopoula 9 Galopoula 10 Galopoula 11 Galopoula 12 Yōtarō Rindō 2 Hyuse Galopoula 13 Katori Unit Tamakoma Second 9 Tamakoma Second 10 Tamakoma Second 11 Tamakoma Second 12 Kuniharu Kakizaki Osamu Mikumo 14 Yōko Katori Tamakoma Second 13 Tamakoma Second 14 Hyuse 2 Osamu Mikumo 15 Chika Amatori 6 Tamakoma Second 15 Tamakoma Second 16 Tamakoma Second 17 Tatsuhito Ikoma Tatsuhito Ikoma 2 Ōji Unit Kazuaki Ōji Tamakoma Second 18 Tamakoma Second 19 Hyuse 3 Hyuse 4 Tamakoma Branch 4 Tamakoma Branch 5 Yuzuru Ema 2 Tamakoma Second 20 Osamu Mikumo 16 Tamakoma Second 21 Suzunari First 2 Suzunari First 3 Tamakoma Second 22 Tamakoma Second 23 Hyuse 5 Hyuse 6 Azuma Unit Azuma Unit 2 Hyuse 7 Eizō Netsuki Osamu Mikumo 17 Ninomiya Unit Chika Amatori 7 Kazuma Satomi Takuma Yuba Tamakoma Branch 6 Tamakoma Branch 7 Yuba Unit Ninomiya Unit 2 Hyuse 8 Yuba Unit 2 Hyuse 9 Chika Amatori 8 Yuba Unit 3 Yuba Unit 4 Masataka Ninomiya 3 Masataka Ninomiya 4 Osamu Mikumo 18 Chika Amatori 9 Tamakoma Second 24 B-Rank Middle Group Final Round B-Rank Middle Group Final Round 2 B-Rank War's End		The B-Rank Rank Battles Begin Suwa Unit and Arafune Unit Start-Up! Mikumo Unit The Brash Rookie Kō Murakami of Suzunari First Nasu Unit's Choice A Battle in Bad Weather What Decides the Battle The Ace's Willpower The Captain's Pride And Towards Tomorrow The Prisoner from Aftokrator No. 1 Shooter: Masataka Ninomiya Sharpened Fangs The Battle of the Top B-Rank Teams The Targeted Tamakoma Battle Royal The Captain's Duty A New Threat The Evolving Mikumo Unit To The Future

Expedition Selection Exam Arc

Expedition Selection Exam arc
Manga		Anime
Number of Chapters		Number of Episodes
Ruka Shinoda Yōtarō Rindō 3 Galopoula 14

Anime-Exclusive

Fugitive Arc

Fugitive Arc
Tamakoma Second attended the training camp in Shizuka City. They met Xeno, a genius Trion Soldier engineer, along with Lilith, a Trion Soldier, who were running away from their planet - Ergates. Gieve and Charon were chasing after them in order to retrieve Lilith to prevent information on Trion Soldier technology from getting leaked. Tamakoma Second cooperated with Xeno and Lilith to stave off Gieve and Charon's attacks while waiting for their opportunity to leave Earth.
Manga		Anime
Number of Chapters	N/A	Number of Episodes	15
		Fugitives from Another World Invisible Assailants Xeno's Trion Warriors The Sunset of Miden What Must Be Protected The Offensive of Gieve Dead or Alive Mystery of Lilith Xeno and Lilith Captured Osamu Two Black Triggers Yōtarō's Adventure Truth and Lies Gieve and Charon A Reversed Future