Despite Having Such A Good Budget, Promising Actors, And Pretty Decent Plot, This Series Remained An Average And Time Pass Series.
The Primary Genre [THRILLER] There Is No Thrill In The Series After The Second Episode, The Main Plot Suddenly Disappeared And Came Back In The Final Episode.
The Secondary Genre [MYSTERY] And I Still Didn't Find Out What Is Mysterious Here, Everyone In The School Knows Who Is There For Revenge And FL Also Knows Who Is Threatening Her With Videos.
The Third Genre [ROMANCE] Is There Any Romance They Are Just Using Eachother for Their Profit Or Casually Having Intimacy As Their Tool Of Pleasure.
The Last But Not The Least [YOUTH] It Is A Youth Drama But Everyone Here Are Acting Like An Middle Aged Person That They Are Holding Some Influence Of Their Own, And The Point Where They Want To Handle Situations With Maturity They Are Acting Like 8 Graders, Like You Hit Me I Hit You Too...

And The Character Who Has Most Of The Screentime Kang ha, He Took Admission In Jooshin To Fight Against The Bullies And After Sometime For The Inequality Of Jooshin System, But The Bullies Are Still in The School And The System Is Still The Same The Scholarship Students Still Can't Do Anything...

SOME POSTIVES POINTS OF HIERARCHY.
1. The Production Quality Is Just Amazing. Set Designing Is Good And Quality Looks Very Premium As They Mentioned Jooshin High School As The Prestigious School In Korea.
2. All Actor Are Good And Did Their Job Pretty Well, But The Two Male Leads Lee Chae Min And Kim Jae Won Carried The Whole Show.
3. The Best And The Coolest Thing Of The Series Is Its Camera Work And Sound Design. DOP And The Sound Director Did An Fabulous Job..

Overall It Is An Average Series But If The Post Credit Scene Indicating The Chances Of Part 2.
And, Is The Student Died In Class Is Killed By Kang Ha? Is He Out For Blood And Revenge?
If That's The Case Then Its Pretty Decent Prequel.