Dohoon can’t find a reason to live. He hoped to get a fresh start at his new high school, but things are no different—the bullies make fun of his limp and no one wants to be his friend. Then one night, he runs into a classmate, Aji... Having seen something he shouldn’t, the two make a deal: Aji will protect him for the time being, but when he turns 20, Dohoon will have to pay up.