"God of High School" is an all-styles martial arts tournament for high schoolers from all over Korea. Jin Mori, who lives on his own after parting ways with his grandfather Taejin at a young age, is on his way to the preliminary for his region when he ends up chasing a snatcher. In the midst of his pursuit, he meets Han Daewi and Yoo Mira, two other high schoolers on their way to participate in the preliminary. The only thing on the line is your pride! The only thing you can trust is your fists! Choose any wish, and it will be granted! Such is the power of God! So begins the battle royal featuring the most powerful contenders from all over…

Daewi shows no mercy in his fight against Mira with the goal of getting the money to help his friend, Woo Seungtae, who suffers from an incurable disease. Mori handily defeats his own semifinal opponent, Brazilian jiu-jitsu user Byeon Jaehee, but is angered by Daewi’s method of defeating Mira by targeting her injuries. Daewi, meanwhile, learns that Seungtae has taken a turn for the worse and strengthens his resolution even further. Then, amidst all this, Mori and Daewi face each other in the final round.

The national God of High School tournament will be a team battle between teams formed from the top three participants in each regional preliminary. Mira wins the battle for third place, meaning she will compete in the nationals with Mori and Daewi. Mujin explains to the other administrators that this is all part of the search for the one with the potential to be the "Key." At the same time, Mujin puts out a call to The Six, a group of extraordinarily powerful fighters, in order to deal with Nox, another organization searching for the Key.

After learning that his grandfather, Jin Taejin, has been confined, Mori rushes to set him free. Daewi and Mira await his arrival at the tournament with no idea what's going on. With Mori missing and Daewi suspended, Mira is forced to kick off the team match alone. She struggles against her opponent, Marin, who evades her attacks and counters with her own sword. When he calls it a National Treasure, it begins to glow white, and its true form is revealed...

Ilpyo mercilessly beats down Jegal. Just as he's about to deal the finishing blow, Ilpyo sprouts tentacles and ensnares him. With the charyeok Greed, Jegal unleashes the charyeok powers of the others he's absorbed and turns their incredible powers upon Ilpyo. As their battle rages, something changes in the sky over the arena, and it is soon filled with a sword-wielding God and his many followers...

The god that appeared over the arena has been shot down by Jaesan's technique. Mori and the rest have fallen into a huge cave, where they battle against Jegal, who has transformed into a god after absorbing the Key. Mori, Daewi, and Mira face him together, but their attacks don't even reach him, and Daewi is severely wounded protecting Mori from Jegal's vicious onslaught. As the situation grows desperate, a memory that had remained dormant in Mori's mind all this time reawakens...