Thiên đường của những chú cừu non

"Freiyard" is a world where steam engines and magic coexist. With a warm climate and benevolent rule, culture has developed rapidly, public order is good, and the standard of education keeps rising—a peaceful local city. It is a core city of the central kingdom and one of the six great cities surrounding the central royal domain "Uraisgau." It happens to face the royal domain and the sea on three sides, as well as the neighboring country "Serbandes," with which relations are relatively good; the climate is stable and the atmosphere relatively relaxed. Its main industries are fishing and industry (precision machinery and the like); it was once one of the few granary regions, and now it can only just feed itself. There has been no war here for nearly a hundred years, and public order and cultural standards are high. This year it has stepped up its efforts in education. In Freiyard there is a school, "St. Vermillion Academy," which worships the god of compassion, "Terezato," and is very famous among seminaries. Its educational principle is to cultivate students who excel in both letters and martial arts, and most students aim to improve their holy magic skills through theology. Masters of holy magic may choose to join the Holy Knights, but there has been no war here for nearly a hundred years, and the Holy Knights today are merely a prestigious name—or rather, a profession treated like famous entertainers. Even so, the students in the elite class work hard, but the protagonist... doesn't study properly...
As the hot summer cools into autumn... Ryu... is worrying. The end-of-term placement exams (this school's enrollment period is September) are over, and classes are assigned based on results. This school exists for advancement to higher education and takes "unity and mutual aid" as its educational principle. That sounds nice, but in fact it means "no matter what happens, the group takes responsibility, and if punishment is due, everyone is punished." In a class with decent grades, friendship might develop. But our class has gathered a bunch of troublesome problem children.
I don't think of myself as a model student. If not for the coercion of my old man, a priest at a small church, a lazy person like me would never go to a boring place like a seminary. The other students... Julio, the womanizer, and Leo, the sword fanatic. The reliable girls: the airheaded Claire, and the "Jewel Sisters"—martial arts expert Tina and black magic expert Elena... Why did so many problem children gather here! Even I find it unbelievable!?
And the nun who serves as our instructor turns out to be my own big sister Aina—I simply can't believe it. My sister Aina is kind to people and highly skilled in holy magic, and the people around call her things like "the Saint of Freiyard"... but in reality she's a crybaby, clingy, and a severe brocon; teaching students is completely outside her field. Anyway... just spare me the clinging in front of other people...
One day... I heard a transfer student is coming to our class. Apparently she's a girl from the East who graduated early with excellent grades from a school over there—quite the talented girl. As expected, she majored in Eastern divine arts there, and she's studying abroad here to learn other schools and broaden her horizons, I suppose... Anyway, our state religion doesn't suppress other religions and often accepts people from other sects.