It was sad enough being B-grade, but to think I'm F-grade...

The guide for the peerless S-class Esper, Cheon Yeon-ho, is only B-class? ‘Did anyone beg me to be his guide…!’ Worn out in both body and mind by the cold treatment from Cheon Yeon-ho and the judgmental glares of people who looked down on him for being an insufficient guide, Ha-min suffers an unexpected accident inside a dungeon one day. After that, he suddenly wakes up in a strange body. “You’re Kang Gyeo-wool, right?” “…Excuse me?” The owner of this body is Kang Gyeo-wool, 20 years old, and an F-class guide. It was miserable enough being B-class; how much worse would it be as an F-class? To make matters worse, he becomes entangled once again with the S-class Esper Cheon Yeon-ho, wh...