In the second episode of "Nanatsu no Maken ga Shihai suru," the day begins with the students waking up and preparing for their first day of school. The main characters, including Oliver, Pete, and Nanao, meet for breakfast and discuss their excitement and fears about the upcoming day.

The first class of the day is swordsmanship, taught by instructor Luther Garland. He explains the history and significance of sword arts and emphasizes the concept of "one step, one spell" for close combat. For demonstration, he asks for volunteers for a duel. Nanao eagerly volunteers and is joined by Oliver. Despite the instructor's initial concerns about Nanao's lack of experience, the duel proceeds. The duel grows intense, and both participants unconsciously break the anti-death spell. The instructor ends the duel before it can escalate further.

The second class is magic, where teacher Frances Gilchrist highlights the importance of magic compared to physical weapons. The third class is Magical Biology, taught by Vanessa Aldiss. The students are tasked with feeding magical silkworms the right amount of magic so they produce cocoons. If they feed them too much, the silkworms turn into monsters. The task proves difficult for the students, but most manage to succeed.

Later, Katie, a student who struggled with the task due to her love for animals, is comforted by Oliver.

The day ends with the students returning to their rooms. However, Pete realizes he forgot his book in the classroom. As he, Oliver, and Nanao go to retrieve it, they encounter the upperclassmen Ophelia Salvadori and Cyrus Rivermoore. The encounter is tense, as Ophelia displays a strange ability to inflict pain, and Cyrus shows a disturbing interest in the first-year students. The episode ends with the first-years fleeing back to their rooms.