The class "KO One" takes students with all kinds of issues. This semester, a transfer student tries to vie for the "boss" position with Da-dong.

The sound of Ding Xiao-yu playing the piano dissolves the tension. Da-dong lends out a helping hand when Arthur's father is in danger.

On the way back from visiting her brother's tomb, Tian Xin is kidnapped and forced to resign her teaching job. Da-dong's buddy returns to the country.

Jin Bao-san witnesses a side of Lei Ke-si that is unknown to others, but Da-dong calls on his classmates to take side jobs to help pay Ke-si's debt.

Lei Ke-si goes out of his way to please all the teachers and classmates while framing Arthur, making it difficult for the latter to reveal the truth.

An unexpected visitor turns up at Da-dong's house. Dean Jia Yong and Lei Ke-si both want to turn An-qi into their pawn.

A madly jealous Lei Ke-si continues to mislead An-qi as he tries to take this opportunity to confess his love to her. Arthur devises a scheme.

Lei Ke-si finally shows his true colors and launches a surprise attack on Da-dong. The two fight fiercely, yet one of them stops at the last moment.

Da-dong and An-qi gets back together as a lovey-dovey couple. A difficult decision awaits Tian Xin after she gets a new boyfriend.

Da-dong begins to rebel against the homeroom teacher and reverts back to his old aggressive self, which arouses the suspicion of An-qi and Arthur.

Da-dong wants to embarrass Shao-zong, who ends up winning the admiration of his classmates. Tian Xin uncovers the truth behind Shao-zong's exhaustion.

The entire class comes up with an idea to help Shao-zong reconcile with his biological mother. An-qi and Xiao-yu seem to be more than friends.

A mystery man appears multiple times but leaves each time when Tian Xin arrives. Da-dong's pastor dad has been hiding an astonishing secret.

The class teacher leaves without a word. An-qi comes over to comfort an unhappy Da-dong, who loses consciousness in an instant.

Da-dong receives a letter from An-qi. Being taken by surprise, he acts in a flurry and falls prey to Hei Long and Wu Shi.

Two sisters transfer to the class, and the younger one falls in love with Arthur at first sight. The new teacher puts the class in an uproar.

A comic set that predicts the future is about to be reprinted, which not only attracts great attention, but also people who intend to kill the author.

Da-dong sets out to advance his fighting power. Arthur becomes unusually short-tempered after being injured by his own sword in the stone.

Arthur becomes so delirious that he wants to harm those around him, but a powerful force of energy stops him at the critical moment.

Arthur must face a stern challenge. Wu-xiong's body is rapidly aging. A familiar face returns.

Da-dong's parents are missing, now even Arthur's father disappears for no reason. Everyone prepares for a battle of life and death.

Da-dong and Wan-jun are ambushed as they investigate the reason of the abnormal fighting count. Lei Ting cannot tell how she feels about Wan-jun.

Everyone is shocked when the new class teacher shows up. A letter Lei Ting receives prompts her to confront the past and face the future.

The KO List undergoes dramatic changes. Da-dong is assigned to return to class KO One to investigate, where he reunites with the teacher, Tian Xin.

After falling through the crack of time and space, Da-dong finds that everything familiar has changed. It turns out that ten years have gone by.