The story begins with Police Officer Choi Siwon taking in charge of Seoul City Police. He learns from his suboridinate Donghae that the city is still ruled by underworld don Kangin. Siwon seems interested in his new cases dealing with underworld drug mafia. 

 

 

Max Changmin is Kangin's lead henchman. Kangin acts as a sort of Godfather to him. Changmin has a face-off with Siwon and Siwon gets injured in the fight. Changmin beat up Siwon and escape from the scene.

 

 

 Siwon later is surprised to see Changmin during a train journey but it turns out that it is Changwook, Changmin's identical twin, who, unlike Changmin, is a well-educated and righteous person.

 

 

Siwon visits their family home in Busan to confirm the facts. He learns that Changmin, despite being from a well-off family and being topper at school, ran off during his teenage and joined the gangs of Seoul owing to a punishing father. Siwon also meets Changmin's uncle Kangta and his daughter Tiffany who is Changwook's fiancée.

 

 

Back in Seoul, Siwon meets Kangin and he introduce Siwon to his lawyer as the officer responsible for destroying Mokpo underworld and as the son of former Deputy General of Police, Choi Siwan.

 

Later , it is hinted that Kangin is responsible for the death of Siwon's father and Siwon is seeking revenge.

 

 

Changmin's best friend Minho works for Eric, the leader of the rival gang. Despite this, they keep their friendship alive.

 

Changmin lives in a flat provided by Kangin and has a deep relation with neighbouring family of Kyuhyun and her mother Leeteuk, whom he calls Mama. Kyuhyun is in love with Changmin but he wears a stern face to hide his love.

Kyuhyun: Chwang.....

Changmin: Hmm

Kyuhyun: Minnie.....

Changmin: What!!!

Kyuhyun: Chwangie pabbo....

Changmin: What the hell do you want?!

Kyuhyun: I.... I love you...

Changmin: Don't waste your time on me.

Kyuhyun: Chwang... I... really...

Changmin: I got some jobs to do. Go home before sunset.

Kyuhyun: ..... hiks.... hiks... why.... i.....

 

 

Changmin walked away from Kyuhyun with heavy heart.

 

 

Changwook visits Changmin at his flat and befriends Kyuhyun. Changmin becomes visibly jealous with the affection and respect that Kyuhyun shows to Changwook. Changwook requests Changmin to return home, however Changmin refuses as he still strongly hates his father.

 

 

Changmin: It's been a while I haven't seen you Cho Kyuhyun.

Kyuhyun: I thought you don't want me near.

Changmin: He already have a fiancee.

Kyuhyun: What???

Changmin: Wook already have a fiancee. Well my uncle Kangta's daughter, Tiffany.

Kyuhyun: Wow! Daebak!!!

Changmin: You are not sad?! Knowing he already engaged?!

Kyuhyun: This is the longest conversation we ever had. Wow you are so handsome when you talk. You voice is soo manly and... Wow.... 

Changmin: Who am I talking to!!! You are completly hopeless.

Kyuhyun: Why you talking about Wookie hyung? 

Changmin: Wookie hyung?!!!! You never called me hyung...

Kyuhyun: I wanna call you oppa... Minnie Oppa... neomu neomu saragheyo....

Changmin: Huh!!! You are blindly in love with me. God!!!

Kyuhyun: I wanna kiss you Oppa...

Changmin: ert!!!

Kyuhyun: Only for you Oppa....

Changmin: Stop touching my cheeks Kyuhyunie...

Kyuhyun: Oppa.... you .... called me .... Kyuhyunie????.... Wow... 

Changmin: Oho!!!

 

 

 

Changmin murders Suho, a close associate of Eric which upsets him greatly following Kangin's command. Siwon councils Eric and he provides information on secret godowns. Siwon raids the godowns and arrests some associates of Kangin. Kangin senses danger and he convinces Changmin to kill Eric which he does with a single shot from behind with great grief.

 

 

Back home Changmin finds Mama murdered and realize that Kangin ordered the murder. Changmin tries his best to calm Kyuhyun. But he himself was not okay to accept that Leeteuk was no longer with them.

 

 

Changmin visits Kangin and gets furious with him. He kills the man who has murdered Mama Leeteuk and quits the gang. In respite Kangin arranges a 'Shoot at sight' order against Changmin. Siwon learns this and tries to protect Changmin.

 

 

Meanwhile, Changwook arrives in Seoul to pursue Changmin to attend their sister's wedding. Siwon manages to find Changmin but Changwook is killed in front of them by Kangin's men.

 

 

 

Siwon and Kyuhyun convinces Changmin to pretend as Changwook so as to escape Kangin. Changmin, Siwon and Kyuhyun takes Changwook's body back to Busan. At home, he finds his parents grieving on his death. After the funeral, Siwon returns while Kyuhyun stays for a few more days.

 

 

 

Changmin tries to be Changwook, without knowing anything about him. He find it very difficult and goes lonely most of the times. He enters a long leave from college. He understands how much his father loved him. Also his mother reveals to him that she had understood his identity at first sight. She asked Changmin whether he missed her and dad atleast once. Changmin sobbed in her arms.

 

 

 

Back in Seoul Kangin finds a new hitman Eunhyuk and kills associates to destroy evidence against him. Siwon visits Changmin and request his assistance to destroy Kangin. He tries to provoke Changmin to seek revenge for his brother's death. However Changmin refuses to help as he is trying to carry on his new life.

 

 

 

Changwook gets honoured by a national award for his contributions to bird watching and book. Changmin finds it difficult to face the press interviews following the award. He reveals the truth to his uncle .

 

 

 

Meanwhile, Kangin reads about the award and learns that Changmin has a twin brother. He get alerted immediately and visits Changmin's house pretending to give a compensation to the family for his former employee. Changmin handles the situation well, but Kangin's doubt remains.

 

 

 

 

Kangin abducts Kyuhyun and tracks that Changmin is the one who is alive and tries to get Changmin come back to Seoul.

 

 

 

Finally Changmin decides to go and his father also learns the truth. He arrives in Seoul and takes hand in hand with Siwon. They capture all of Kangin's men in a single night and raids all of his hideouts.

 

 

 

Changmin come to Kangin's Mansion and rescues Kyuhyun. Kangin stands alone helplessly. Changmin tells Kangin that he is defeated, but he does not want to kill him. He hands his gun to Kangin. But instead of killing Changmin, Kangin commits suicide.

Changmin: Kyu....

Kyuhyun: Hmm...

Changmin: Saraghae... Jeongmal Saraghae... Don't leave me....

Kyuhyun: Chwangie pabbo there is no Kyuhyun without Changmin.

Changmin: Kyuhyunie chagiya....

Kyuhyun: Hmm Oppa.....

Changmin: You are making me a ert....

Kyuhyun: Huh?!!! Why are you.....

Changmin: Let's enjoy our honeymoon.... Kajja....

Kyuhyun: Huwee....