Shin Hae, the only S-class guide in all of South Korea, gets a super secret request. They want him to take care of a super young, high-level esper, Sung Taehyun. Five-year-old Taehyun forms a deep bond with Shin Hae, but a sinister organization seeks to exploit his powers, forcing Taehyun to endure a traumatic memory wipe that erases all traces of his beloved guardian