The story begins with the protagonist, Marus Ruina, a young man living a solitary life as an unemployed monster hunter, saving a woman from a monster attack. This woman, later revealed to be Lania, a teacher at the Royal Jupiter Academy, offers him a chance to become an adventurer by enrolling in the academy. Marus, feeling a lack of purpose after the death of his guardian, accepts this offer, marking the start of his journey.
Upon arriving at the academy, Marus is struck by its grandeur, a magnificent castle far exceeding his expectations for an educational institution. He is immediately confronted by a stern, bespectacled elf girl who, due to his unusual appearance and lack of uniform, mistakes him for a pervert or thief. Their tense interaction is interrupted by Lania, who reveals she is a teacher and has brought Marus as a recommended student. The elf girl expresses her dissatisfaction, hinting at the academy's competitive nature and the special status of recommended students who are exempt from the rigorous entrance exams. Lania explains that these recommended students, like Marus, are often envied and sometimes resented by those who passed the exams, as they receive free tuition and are seen as elites.
Marus is brought to the academy director, Cadus Rainer, a seemingly ageless and powerful former adventurer who defeated a Demon Lord. Cadus reveals that Marus is a special case, admitted at their request, and is not obligated to become an adventurer. However, he probes Marus's motivation for joining. Marus, admitting he is bored with his current life and seeks something he cannot obtain alone, confesses his sole goal is to make friends, having never had any in his life. Cadus, intrigued by this unexpected aspiration, agrees to Marus's admission but insists on testing his strength. He proposes a duel against a summoned beast, as he himself, being the director, cannot fight a student.
The entrance exam takes place in a conjured wilderness. Cadus summons an Earth Dragon, a formidable creature. Marus, unfazed, engages the dragon. He initially uses fire magic, which proves ineffective against its rocky scales. He then closes the distance, exploiting a weakness in the dragon's underbelly and delivering a powerful explosive attack. While the dragon is momentarily downed, it is not defeated. Cadus declares Marus has proven his qualifications, but Lania intervenes, urging him to accept the victory to avoid being labeled a "battle-addicted" student, which would hinder his goal of making friends. Cadus, impressed by Marus's potential, proposes a rematch against him directly for his graduation exam.
After his successful entrance exam, Marus is shown to his dormitory. Lania explains the academy's rules, including the importance of the church bells for timekeeping and the availability of a church with a sister who teaches healing magic, emphasizing the academy's neutrality and security measures. She also mentions the upcoming academy-wide competition in three months, where Marus is expected to be a key participant. Marus is assigned a roommate, Elysia Heinest, a young man with a delicate, feminine appearance who is often mistaken for a girl. Despite Elysia's initial shyness and a past incident that makes him hesitant about forming close bonds, Marus quickly befriends him, fulfilling his primary goal.
During their first meal in the academy's bustling mess hall, which accommodates various races, Marus is impressed by the quality of the food, prepared by a talented maid named Nelpha. Elysia is confronted by Sail, a werewolf classmate who bullies him and attempts to intimidate Marus. Marus intervenes, swiftly incapacitating Sail and forcing him to apologize to Elysia. This incident solidifies their bond, with Marus vowing to protect his new friend. Later, in their shared room, Marus learns about the academy's schedule and the importance of the bathhouse. Elysia, still troubled by the earlier encounter and his own past, decides to consult Nelpha about their shared room arrangement for Marus's sake. Marus, meanwhile, finds comfort in the shared living space, a stark contrast to his solitary life. He also learns that the academy has a strict uniform policy, which he will receive the next day.