Main characters ;
Wang Da Dong (汪大東) The ringleader of the school gang "Zhong Ji Yi Ban" (終極一班 / Ultimate Class). Self-confident and stubborn. Acting like an obedient child at home, he keep his parents in the dark about his school life. Everybody in Zhong Ji Yi Ban listens to him. Da Dong is number three on the KO Rank and has the battle level of 9,000. Although Da Dong seems harsh and cold, he is actually a good person at heart and shows his caring side whenever his friends need help. He carries the "Long Wen Ao" (龍紋鏊 / Dragon Tattooed Pan) as his primary weapon. The unique aspect of this weapon is that it can vary its master's fighting count according to the opponent's fighting count; it becomes stronger when fighting strong opponents and remains normal when facing weaker ones (遇強則強、遇弱則弱). ;
Wang Ya Se (王亞瑟) The son of the gangster leader of "Tu Long Bang" (土龍幫). Rich, powerful, self-centered, and his concerns are his looks. Like Da Dong, he has a 3rd position on the KO Rank, his battle level being 9,000. Because he and Da Dong shared the third position, he joined Zhong Ji Yi Ban intending to challenge him. They later became best buddies. His primary weapon is the Shi Zhong Jian (石中劍 / Sword in the Stone), a spiritual dagger created by the wizard
Merlin and used by
King Arthur. When he removes the stone from the dagger, the sword essence will possess Ya Se, allowing him to instantly gain evil powers at the expense of losing control over his own actions. ;
Ding Xiao Yu (丁小雨) Xiao Yu is an exchange student from "Tuo Nan High School" (拓南高中), known as the 4th ranked fighter on the KO Rank, his fighting count being 8,500. He is prone to giving others cold looks if they are not willing to leave him alone. He doesn't like violence. He is known to be great at withstanding constant beating, and he will not fight back. However, if anyone hits his head, he will definitely fight back. He uses his powerful fists as weapons and has the battle level of 8500. Xiao Yu's left fist is said to have the power of an atomic bomb, while his right fist has ten times the power of his left fist. However, if he uses the right hand, he will become unable to use more power within three hours and might risk losing his own life. ;
Huang An Qi (黃安琪) An Qi is daughter of a famous politician and Da Dong's and Lei Ke Si's childhood best friend. She has been in love with Da Dong for a really long time, but never truly knew how he felt. She never knew Lei Ke Si was in love with her. She moved to America five years ago, but during that time she has written over five hundred letters to Da Dong - two letters per week. She never got any response from Da Dong, but he has secretly been collecting and memorizing them. Her love for Da Dong is the reason why Lei Ke Si hates Da Dong. When Lei Ke Si finally reveals his identity as KO. 2 and gets Da Dong into a hospital, she decides to return to America because she believes she caused the rivalry between him and his best friend. Before she leaves, Da Dong tells her that he has been secretly memorizing her letters, so she stayed in Taiwan. ;
Tian Xin (田欣) The homeroom teacher of Zhong Ji Yi Ban (終極一班). Because of her little brother's past, she becomes a teacher, in hopes to getting bad students back on the right track. As a person, she is very nice and likes to babble a lot when she gets angry. At first, Da Dong did not like her at all because of her position as a teacher but was eventually touched by her kindness and decided to let her become their homeroom teacher. ;
Sha Jie (煞姊) Number 13th on the KO Rank. Sha Jie is the leader of the girl gang of the class. She is extremely mean and fierce. She has been in love with Da Dong since before the start of the series, but he hasn't shown any signs of liking her back. ;
Lei Ke Si (雷克斯) Da Dong's childhood friend whom Da Dong has absolute trust in. Lei Ke Si has liked An Qi since they were kids, but because she was in love with Da Dong, he developed a strong hatred for his best friend. In school, he is known as Da Dong's brain. Because of his disguise as a weak kid with good intentions, nobody knows Lei Ke Si is actually KO. 2 - the next strongest fighter on the KO Rank, with a battle level of 10,000. His weapon is "Ah Rui Xi Zhi Shou" (阿瑞斯之手 / Ares' Hand), a metal glove reclaimed from the realm of darkness. ==Episode guide==