To put it mildly, Rin has never felt loved by her adoptive parents, but an arranged marriage at fourteen to a man three times her senior was too much even for a family like theirs. She could think of only one way to escape it - getting to study further. There is, however, only one higher education institution in the whole Nikara Empire that takes up students free of charge, the Sinegard Academy. It also happens to be the best one in the country and notoriously hard to get into. Only those who get the best results in the Keju, an annual examination for prospective students, can enroll there, and even that doesn't guarantee graduation. Thus, Rin has only two years of studies combined with a day job to catch up to her rich and pampered peers who have literally started their way to elite education as soon as they could walk. She succeeds. First, she has to counter accusations of cheating. Then, she has to adapt to a life that has never been meant for her.

It's hard to learn multiple academic subjects from scratch at the same time, but, as Rin proves, it's possible. Winning the acceptance of well-bred snobs is much harder, but she can live without it at all. An unexpected turn of events helps make Rin a fighter unlike any other in her day and age. She basically turns out to be living proof of ancient legends about shamans and their abilities. She can use the immense powers of a particularly belligerent god, powers that can be literally weaponised and thus are of great use to the Nikara army. It seems like Rin no longer has to wonder what she will do after graduation, as she is in for a stable job in the military - until an actual war starts.

To be sure, the overpopulated, quickly modernising Federation of Mugen has already waged two wars against Nikan, the latter of which left Rin orphaned (as it turns out later, more than in one sense). A foreign power stood up for Nikan last time, but Mugen is just too determined to lay its hands on Nikara resources, including human ones, to be afraid of the risks involved. The new invasion is a quick and bloody one, so Rin's country needs everyone capable of bearing arms to come to its defence. Thus, even the students of a top-notch academy end up on the battlefield. As a regular fighter, Rin is predictably mediocre, saved mostly by good luck and an unlikely friend. However, everything changes when her supernatural powers manifest themselves and are put to good use. Rin willingly joins a near-secret unit of shamans and meets several like-minded people there, but she also becomes acutely aware of the hazards and discrimination inseparable from her new job. As she and her new unit start to succeed in the war, all their good work is undone by the enemy's cunning and the intrigue right behind their backs. What is more, Rin learns some ugly truths about both sides of the conflict (you know, the Nikara Empire is called an empire for a reason) that have a direct bearing on her life. It means she could just walk away from the conflict entirely, but she doesn't even consider it an option. How can she focus on saving her own hide when her friends and loved ones are still unavenged? Her righteous anger helps Rin unleash her powers to the full extent, acting in genuine communion with her patron god despite being aware of all the risks that entails. She is going to succeed in her revenge, and it isn't going to be pretty.