Full Spoilers!
After a dramatic incident, young Kang Bok Soo gets expelled from his high school and blacklisted from all other high schools, leaving him unable to graduate and with no good prospects for the future. 9 years later, he returns to that very school to enact his revenge on those that betrayed him.
My Strange Hero (2018) stars Yoo Seung Ho, Jo Bo Ah, & Kwak Dong Yeon in the lead roles.