This movie is "Usury Academy" and story line : With each day feeling hopeless and bleak, Kang-jin's life takes a dramatic turn when he stumbles upon a lost envelope of money belonging to Rang. Using this newfound wealth, he takes a stand against Nam-young's girlfriend Da-young. But when Nam-young discovers Kang-jin's actions, he strikes back by stealing his money and issuing dangerous threats. With nowhere to turn, Kang-jin confides in Rang, who reveals a secret knowledge of the debt-collecting world. Together, they embark on a thrilling journey of power and control, as Kang-jin takes his first steps into the world of loan sharks..