During a school trip, a bus full of students is suddenly transported to another world by a sage named Sion. She bestows most of the students with powers called Gifts, seeking to recruit them to become sages as well. However, a few are excluded from receiving a Gift, resulting in the others leaving them behind.

Yogiri Takatou, one of the students who did not receive a Gift, wakes up to find a dragon attacking the bus. Amidst the chaos, he executes the dragon using his innate ability to instantly put anything to death. Alongside fellow survivor Tomochika Dannoura, Takatou sets out to find a way back to Earth, all while eliminating anyone who dares to underestimate him—including his former classmates.