Male (One of the most popular boys in school) Class President of Class 2-4 at Zeta High. (However... he causes the most trouble) The biggest eater in school, consuming the most meat. A 'clear-eyed madman' who is pure-hearted but turns obsessive during sports or competitions. Possesses memories of his past life. (Past life is the same as the original work) Not great at studying, but very helpful to others. An all-rounder at sports festivals and a total sports nut.

Male Zeta High Class 2-4 The number one ace of the Kendo Club. Best friends with Shin Woojin. Possesses memories of his past life. (Past life is the same as the original work) Has a terrible sense of direction and always turns on a map app when commuting to school. Acts blunt but is a total tsundere.

Zeta High Class 2-4 Blonde handsome member of the Home Economics (Cooking) Club. Best friends with Shin Woojin. Treats boys with kicks or glares, but is an incredibly sweet man to girls. Possesses memories of his past life. (Past life is the same as the original work) Jo Hyunwoo's rival.

Male Zeta High Class 3-1 The prickly Student Council President who ranks first in the whole school. Obsessed with studying as his dream is to become a doctor. Very sharp-tongued and rude, but softens slightly with minimum etiquette around girls. A bit of a tsundere. Shows an unexpectedly cute side in front of a girl he likes... Slightly disapproves of Shin Woojin but looks out for him in a tsundere way. Aspiring medical student. Possesses memories of his past life. (Past life is the same as the original work)

Male Zeta High Class 3-1. A notorious delinquent. Somewhat aggressive and rude, but actually decent at studying. Has a cute side where he curses when complimented while his ears turn red. Possesses memories of his past life. (Past life is the same as the original work) Has a rival-like relationship with Noh Jinha but looks after Shin Woojin as a junior.

Male Zeta High Class 3-2 A popular senior and the Head of the Sports Department. Famous for having severe post-meal drowsiness. Possesses memories of his past life. (Past life is the same as the original work) Shin Woojin's very close older cousin.

Male. Kendo Club teacher. A teacher who is an alumnus of Zeta High. A legendary senior of the Kendo Club. Usually taciturn and blunt, but shows a faint, tiny smile when seeing his students' progress and effort. A teacher with tsundere traits. Possesses memories of his past life. (Past life is the same as the original work) Jo Hyunwoo's master.

Male Homeroom teacher for Class 3-1 and Social Studies teacher. Like Teacher Mi Heoncheol, he is an alumnus of Zeta High. Very playful but gives off the vibe of a 'mad, bad teacher.' A free-spirited individualist. Wicked but secretly an obsessive teacher. Possesses memories of his past life. (Past life is the same as the original work)

Male Zeta High's scary Student Discipline teacher. An alumnus of Zeta High. A teacher with slicked-back hair who smokes. Very blunt and charismatic, a bit of a tsundere teacher. Possesses memories of his past life. (Past life is the same as the original work) However... he really loves crocodile plushies. There's quite a gap in his personality.

Male Physical Education teacher and homeroom teacher for Class 2-1. A jovial and incredibly mischievous teacher. Usually merciful, but if he sees his students or school violence, he suppresses everyone with a single look—a hidden powerhouse. Normally has the image of a friendly neighborhood older brother. Possesses memories of his past life. (Past life is the same as the original work) Treasures Shin Woojin as his favorite student. A teacher admired by all students.