After making friends with his classmates Saga and Fushimi, Ashiya believes the high school life he dreamed of may finally be his. But before he has the chance to enjoy his new life, he's instructed to go to a certain temple alone to find and return a yokai's lost possession. At the temple, Ashiya meets a girl named Fujiwara Zenko, and it seems the lost possession in question has something to do with Zenko's father, the head priest...

When Ashiya begins working part time at the Mononokean, the master Abeno impresses upon him that he should pretend not to see any yokai other than the Mononokean's clients. However, the kind-hearted Ashiya is unable to keep his word, and the yokai won't leave him alone. Based on their surprising strength and numbers, Abeno believes there must be a powerful demon serving as their leader.

Reunited with the yokai he and Ashiya exorcised together, Abeno realizes the Mononokean still needs Ashiya. Abeno suddenly misses him, and with the help of the yokai, he decides to give his idea a try. Meanwhile, Ashiya wonders if the reason Abeno has been absent from school so much is because he's busy exorcising yokai and decides to check out the shrine in the mountains Yahiko mentioned.

Abeno visits the Legislator to inform him that Ashiya is no longer working for the Mononokean. As Abeno rarely comes to visit without his presence being requested, the curious Legislator asks why, but when he hears what Abeno has to say...? Meanwhile, Ashiya stops by the Kiyakudo when he hears from Shizuku, where he runs into the yokai Big Boss Scree, a yokai he previously exorcised, and his children. When they hear that Ashiya is in trouble...?

A yokai worshipped as a kami by humans and known as Okina-sama to other yokai comes to the Mononokean with a request: to send the blind yokai Tomori back to the Underworld. After hearing Okina's story, Abeno and Ashiya immediately head to see Tomori. However, upon seeing how Tomori longs to once again see the sights of the Underworld, he tries to see what he can do before Tomori is returned to the Underworld...

When Ashiya and Abeno smell a yokai on the potatoes Yahiko has been sneaking, they head to the farm where they were grown. There they encounter a yokai calling himself Nobou. Nobou has been attempting to leave the farm, but each time he does, he is enveloped in a strange smoke, forced to witness the events of his past, and returns to where he started. Nobou asked to be exorcised so he can leave the farm, but Abeno notices something about the situation.

The day before he begins attending high school, Ashiya Hanae becomes possessed by a strange fuzzy yokai. Being possessed causes him to fall ill, and while spending the start of his high school life repeatedly making trips to the nurse's office, he comes across the contact information of the Mononokean, which specializes in exorcising yokai, and decides to call them. When Ashiya finally visits the Mononokean, he meets the morose master Abeno Haruitsuki.

The last enemy on the continent is the Republic, and the Empire has come up with a bold plan to take them out. Of course, Tanya is sent to the forefront of this operation, and is forced to take on the entire Republic army by herself while the Empire stages a faked withdrawl. Then it's off for a ride on a rocket as she heads straight into the heart of enemy territory!

The war with the Entente Alliance is done, and it's back to the Rhine for Tanya and her forces. The Republic troops are highly trained, well-equipped, and stronger than any she's faced before. And in a distant hospital, a former Kingdom officer wakes up, with a mission from God imprinted on his mind...

The Empire is launching a seemingly foolish attack on the Entente Alliance in the middle of winter. They lack the supplies to successfully invade. Tanya realizes that this attack is a feint intended to distract from a fjord landing mission. Sure enough, she is sent to lead the invasion of the fjords, and silence 20 cannon emplacements in time for the fleet to land and the Imperial forces to disembark.

After her easy victory over Dakia, it's time for a more difficult mission: aiding the destruction of the Entente Alliance to the north. The Alliance is being backed by the strong powers, and has equipment and training that in some cases rival the Empire. When Tanya arrives, the Alliance is striking a critical supply base with a bombing raid, and the local Empire force are too overwhlemed to defend against it. Can she get there to hold them off in time?

Tanya's new battalion is off the ground and running, and it's time for them to do their first mission: fight back a massive invasion by the Dakian Dukedom to the southeast. The enemy army numbers in the hundreds of thousands, but they've brought no air units at all, which makes them easy pickings for Tanya's highly trained force. After wiping out the enemy army, she heads straight for the enemy capital and launches an attack there.

Tanya is now living life on easy street, as a highly-respected student at the military university. She's so highly respected, in fact, that one of the Empire's chief military planners asks her for her opinion on the course of the war. Eager to show off her intellect (and hopefully land herself a cushy job in the planning department), Tanya comes up with a plan of astonishing insight and intelligence. Her idea backfires, however, when she turns out to be a little too smart for her own good...

After her stunning success with her first mission, Tanya is assigned to test a new piece of technology: a highly unstable prototype calculation jewel. This jewel offers her unparalleled power, but just using it risks her life. Tanya is determined to get out of this project and on to someplace easier and safer (like the front lines of the war), but Being X has other ideas...

The secret of Tanya's birth is revealed. Tanya was a cold and unemotional Japanese salaryman who was pushed in front of a train by a man he laid off. An infuriated godlike creature named "Being X" sent him to this world, and reincarnated him as a baby girl... with no promise that he would ever be reincarnated again. Now Tanya has to survive, because this is all she's got!

Tanya just barely manages to restrain herself from disobeying her superior officers and attacking the Republic remanents. But the Republic forces have escaped overseas, and vowed to fight to the bitter end. The Empire has been victorious, but in its victory it has terrified the rest of the world and spurred them to action. Is true victory possible at all?

Tanya's diminished smaller company attack the battalion of Allied Kingdom mages rather than retreat. Their company use their altitude advantage but suffer heavy losses, especially when Colonel Sioux uses an illegal Trench Gun.

Tanya's spectacular mission is a success, and the Republic is surrounded and crippled. But on her way back, she runs into a group of allied mages, lead by Anton Souix, the man she crippled once more. He's back, and powered by Being X, and his one mission in life is to take down the Devil of the Rhine!

The Empire is a powerful military nation on a continent that looks much like early 20th century Europe. But in this world, magic is real. The Empire is involved in a war against the Entente Alliance, and fighting a poorly executed delaying action in the northern theater. Second Lieutenant Tanya Degurechaff leads a small platoon of mages. But there's something unusual about this lieutenant... she's only nine years aold!

Naho feels relieved now that she has the support of all her friends. On top of that, Kakeru and Naho begin to get even closer. Finally, the day of the athletic festival comes. What do Naho and the gang do to insure Kakeru can enjoy the festival from the bottom of his heart?