Off-duty Japan Self-Defense Forces (JSDF) officer and otaku, Youji Itami, is on his way to attend a doujin convention in Ginza, Tokyo when a mysterious portal in the shape of a large gate suddenly appears. From this gate, supernatural creatures and warriors clad in medieval armor emerge, charging through the city, killing and destroying everything in their path. With swift actions, Youji saves as many lives as he can while the rest of the JSDF direct their efforts towards stopping the invasion. Three months after the attack, Youji has been tasked with leading a special recon team, as part of a JSDF task force, that will be sent to the world beyond the gate—now being referred to as the "Special Region." They must travel into this unknown world in order to learn more about what they are dealing with and attempt to befriend the locals in hopes of creating peaceful ties with the ruling empire.
Episode 1
A mysterious “gate” appears in Tokyo releasing mythical creatures that wreak havoc. Itami, who is part of a special JSDF unit, helps with evacuations.
Episode 2
In the “Special Region,” JSDF is able to push back the enemy army. Itami joins a recon team aimed at forming a friendly relationship with the locals.
Episode 3
Itami's 3rd Recon Unit saves an elf from a village attacked by the Fire Dragon. The villagers of Coda decide to flee to safety
Episode 4
The 3rd Recon Unit returns to base with the refugees. Tuka, Lelei and Rory use this time to learn more about each other and strengthen their bond.
Episode 5
The 3rd Recon Unit meets Imperial Princess Piña. Itami decides to protect Italica after hearing that Allied soldiers-turned-bandits have attacked.
Episode 6
The 3rd Recon Unit battles the bandits in Italica. The battle changes course when air support arrives. Piña is stunned by the JSDF’s military might.
Episode 7
While returning from Italica, Itami is captured by the Empire’s Rose Knights. Concerned about JSDF’s response, Piña makes a proposition.
Episode 8
Piña, Itami and the others visit different government offices for negotiations. Piña is awestruck by the impressive skyscrapers and people of Tokyo.
Episode 9
Itami hides Tuka and the others in his ex-wife’s apartment. As Piña and Bozes go to the library, Itami meets his old friend, the Minister of Defense.
Episode 10
When operatives from the U.S., China and Russia approach, Rory uses her unparalleled combat abilities to join in the three-way fight.
Episode 11
Five months since the war began, the local refugee camp near the Alnus base has become a town. Piña begins peace negotiations with key Empire nobles.
Episode 12
A Dark Elf named Yao asks the JSDF to help drive the Fire Dragon from her hometown. She is mistakenly arrested until Lelei volunteers to interpret.
Episode 13
Piña holds a party to advance peace negotiations. Seeing the JSDF’s power, the senators choose peace. Just then, the pro-war Prince Zorzal arrives.
Episode 14
After an earthquake strikes the Imperial Capital, Piña brings Itami and the others to meet Emperor Molt. However, they are joined by Prince Zorzal.
Episode 15
Itami rejects a mission from Yanagida to exterminate the Fire Dragon. Yao tells Tuka that the dragon killed her father, but she refuses to accept it.
Episode 16
Itami heads to Elbe with Tuka, Lelei and Yao to destroy the Fire Dragon. When General Hazama learns of this mission, he prepares battle support.
Episode 17
Heavily armed, Itami and the others head to the Fire Dragon’s nest in the Tuba Mountains. Rory sees the dragon in the distance as they set explosives.
Episode 18
Itami and the others finally defeat the Fire Dragon and save Tuka from her trauma. After being punished, Itami receives new orders.
Episode 19
Emperor Molt collapses at a ceremony and Prince Zorzal declares that he will lead the Empire. A sage named Mimoza tells Itami the secrets of the Gate.
Episode 20
Prince Zorzal suppresses political opposition by arresting anti-war senators. Itami and the others hide after an attempt on Lelei’s life.
Episode 21
A state official visits the Prime Minister to bolster peace. Itami and the others visit Rondel, home of the Magic Academy, for Lelei to take a test.
Episode 22
Zorzal’s Imperial Army and the Rose Knights wage an intense battle. Itami learns of an assassination plot as Lelei’s exam approaches its end.
Episode 23
The JSDF aims to save the Japanese people and pro-peace nobles. Itami rushes to the Imperial Capital after hearing of Piña’s imprisonment.
Episode 24
Itami and the 3rd Recon Unit head to the Imperial Palace to save Piña and the Emperor. However, Prince Zorzal is waiting for them with a giant Orge.
